Application of fiber element in the assessment of the cyclic loading behavior of RC columns

Sadjadi, R.,Kianoush, M.R. Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.3

This paper studies the reliability of an analytical tool for predicting the lateral load-deformation response of RC columns while subjected to lateral cyclic displacements and axial load. The analytical tool in this study is based on a fiber element model implemented into the program DRAIN-2DX (fiber element). The response of RC column under cyclic displacement is defined by the behavior of concrete, and reinforcing steel under general reversed-cyclic loading. A tri-linear stress-strain relationship for the cyclic behavior of steel is proposed and the improvement in the analytical results is studied. This study only considers the behavior of columns with flexural dominant mode of failure. It is concluded that with the implementation of appropriate constitutive material models, the described analytical tools can predict the response of the columns with reasonable accuracy when compared to experimental data.

Preparation of Cu-MgO catalysts with different copper precursors and precipitating agents for the vapor-phase hydrogenation of furfural

Samahe Sadjadi,Vahid Farzaneh,Samira Shirvani,Mohammad Ghashghaee 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.3

This article presents the effects of three copper precursors and four precipitating agents on the catalytic performance of the corresponding co-precipitated Cu-MgO catalysts in the vapor-phase hydrogenation of furfural. The chemical and physical properties were analyzed by means of XRD, BET, SEM, and EDX techniques. The nitrate precursor provided the highest performance (conversion of ~89%). Whereas, the catalyst prepared with NaOH was the most efficient (furfuryl alcohol yield of >90%) during 240min; the most durable conversion (~95%) was assured with Na2- CO3, and the highest selectivity to furfuryl alcohol (>97%) was achieved with K2CO3 as the precipitating agent. The least efficient catalyst (prepared with ammonium carbonate) led to 5-methylfurfural and 2,2-methylenebisfuran as the main byproducts. The major byproducts over the rest of the catalysts included tetrahydrofurfuryl alcohol, furfuryl ether, 1-pentanol, and 2-methylfuran. An increasing trend of furfuryl alcohol selectivity with time-on-stream was evident for all of the catalysts.

Application of fiber element in the assessment of the cyclic loading behavior of RC columns

R. Sadjadi,M.R. Kianoush 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.34 No.3

This paper studies the reliability of an analytical tool for predicting the lateral loaddeformation response of RC columns while subjected to lateral cyclic displacements and axial load. The analytical tool in this study is based on a fiber element model implemented into the program DRAIN-2DX (fiber element). The response of RC column under cyclic displacement is defined by the behavior of concrete, and reinforcing steel under general reversed-cyclic loading. A tri-linear stress-strain relationship for the cyclic behavior of steel is proposed and the improvement in the analytical results is studied. This study only considers the behavior of columns with flexural dominant mode of failure. It is concluded that with the implementation of appropriate constitutive material models, the described analytical tools can predict the response of the columns with reasonable accuracy when compared to experimental data.

Polypyrrole-polyaniline/Fe3O4 magnetic nanocomposite for the removal of Pb(II) from aqueous solution

Seyed Abolfazl Seyed Sadjadi,Amirhossein Afshar,Afsaneh Mollahosseini,Mohammadreza Eskandarian 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2

Lead ion which is engaged in aqueous solution has been successfully removed. A novel technique was utilized for the separation and absorption of Pb(II) ions from aqueous solution. Magnetic Fe3O4 coated with newly investigated polypyrrole-polyaniline nanocomposite was used for the removal of extremely noxious Pb(II). Characteristic of the prepared magnetic nanocomposite was done using X-ray diffraction pattern, Field emission scanning electron microscopy (FE-SEM), Fourier transform-infra red spectroscopy (FT-IR) and energy dispersive x-ray spectroscopy (EDX). Up to 100% adsorption was found with 20mg/L Pb(II) aqueous solution in the range of pH=8-10. Adsorption results illustrated that Pb(II) removal efficiency by the nanocomposite increased with an enhance in pH. Adsorption kinetics was best expressed by the pseudo-second-order rate form. Isotherm data fitted well to the Freundlich isotherm model. Upon using HCl and HNO3, 75% PPy-PAn/Fe3O4 nanocomposite, desorption experiment showed that regenerated adsorbent can be reused successfully for two successive adsorption-desorption cycles without appreciable loss of its original capacity.

Pd Nanoparticles Immobilized on Boehmite as an Efficient Heterogeneous Catalyst for Lubricant Hydrogenation

Asadi Zahra,Sadjadi Samahe,Bahri-Laleh Naeimeh,Nekoomanesh-Haghighi Mehdi 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.3

To furnish high-quality poly-alpha-olefi n oils, hydro-fi nishing under mild reaction conditions by a novel heterogeneous catalyst was accomplished. In this regard, Pd nanoparticles were immobilized on Boehmite. Then, the eff ect of hydrogenation variables, i.e., catalytic loading, reaction pressure, and temperature on the catalytic effi ciency, was investigated with response surface method. According to the results, a hydrogenation effi ciency of 85% was obtained at the optimum reaction conditions of T = 130 °C, P = 8 bar, and catalyst dosage = 5 wt%. Notably, the catalyst was recyclable for four runs with insignifi cant leaching of palladium nanoparticles. The comparison results suggested Pd/Boehmite catalyst as an appropriate alternative to the commercial Pd/Alumina and Pd/Silica. Hot fi ltration test also approved heterogeneous nature of catalysis.

Development and Pilot Testing of the Snackability Smartphone Application to Identify Healthy and Unhealthy Snacks

Lukkamol Prapkree,Masoud Sadjadi,Fatma Huffman,Cristina Palacios 대한의료정보학회 2019 Healthcare Informatics Research Vol.25 No.3

Objectives: Snacks contribute to the diet quality in youth, which is often poor. Although the US Department of Agriculture (USDA) has guidelines for healthy snacks, this is lost in translation when youth are choosing snacks. To develop a userfriendly app to help identify healthy snacks based on the US Department of Agriculture guidelines and evaluate the app’s feasibility, usability, satisfaction, and acceptability. Methods: The ‘Snackability’ app was developed following the ADDIE (analysis, design, development, implementation, and evaluation) model. The app was pilot tested for 2 weeks among college-age students (18–24 years) using questionnaires and focus groups. Based on the feedback received, the app was improved, and pilottested again. Results: The app had a simple score (–1 to 11) and feedback (the higher the score, the healthier the snack is). The 1st pilot test among 12 students showed that the app’s feasibility and usability were >50% (p < 0.05). Participants reported that the app was a good way to help individuals select and consume healthy snacks and suggested improving the search process and including average score reports, a ‘consumed history’ tab, gamification, notifications, and the option to add snacks not found. These were incorporated into the 2nd version of the app, which was pilot tested among 8 students. Feasibility, usability, and acceptability of the 2nd version were >50% (p < 0.05). Additional suggestions were to include images for serving size, snack alternatives, and barcode scanning, which were incorporated into the 3rd version. Conclusions: Snackability app was feasible, usable, satisfactory, and acceptable, and several features were improved as suggested by participants.

Lattice model for spontaneous imbibition in porous media: the role of effective tension and universality class.

Lee, Deok-Sun,Sadjadi, Zeinab,Rieger, Heiko Published by the American Physical Society through 2014 Physical review. E, Statistical, nonlinear, and so Vol.90 No.1

<P>Recently, anomalous scaling properties of front broadening during spontaneous imbibition of water in Vycor glass, a nanoporous medium, were reported: the mean height and the width of the propagating front increase with time t both proportional to t(1/2). Here, we propose a simple lattice imbibition model and elucidate quantitatively how the correlation range of the hydrostatic pressure and the disorder strength of the pore radii affect the scaling properties of the imbibition front. We introduce an effective tension of liquid across neighboring pores, which depends on the aspect ratio of each pore, and show that it leads to a dynamical crossover: both the mean height and the roughness grow faster in the presence of tension in the intermediate-time regime but eventually saturate in the long-time regime. The universality class of the long-time behavior is discussed by examining the associated scaling exponents and their relation to directed percolation.</P>

Preparation, Characterization, and Application of Electrospun BAG/CMC/β-CD Nanofibers for Flutamide Drug Delivery

Tajik Masoumeh,Seyed-Sadjadi Mirabdullah,Zare Karim,Farhadyar Nazanin 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.3

In this study, using a combination of bioactive glass (BAG), carboxymethyl cellulose (CMC), and β-cyclodextrin (β-CD), a novel nanofi ber network was fabricated through the electrospinning method. The biocompatible BAG/CMC/β-CD nanofi bers (NF) were optimized for the controlled release of fl utamide, a hydrophobic anticancer drug, which was immobilized on the surface of nanofi bers through chemical conjugation. The synthesized nanofi bers were characterized by various analytical techniques, including X-ray diff raction analysis, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, the Brunauer–Emmett–Teller specifi c surface area, fi eld emission scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and UV–Vis Spectroscopy. The drug loading and in vitro drug release studies at a pH of 7.4 investigated the high loading effi ciency at 99.65% and the release without an initial burst of a high dosage of the drug in a few hours. The drug release achieved 100% within 12 h, following a sustained release pattern due to the slow degradation of the matrix. The fi ndings suggest that BAG/CMC/β-CD NF could be a promising candidate for the fl utamide drug delivery system due to overcoming the challenges of its poor bioavailability and low aqueous solubility.

Simulation of continuous catalytic conversion of glycerol into lactic acid in a microreactor system: A CFD study

Pooya Jalal Sahandi,Mohammad Kazemeini,Samahe Sadjadi 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

Hand in hand with the flourish of the biodiesel industry, glycerol (GLY) as an inconvenient by-product hasgenerated environmental and sustainability concerns. Devising measures for efficient transformation ofGLY into value-added products is a promising solution. In this contribution, the transformation of GLYto lactic acid (LA) as a valuable chemical was investigated in a continuous process for industrial applications. In this regard, a catalytic method using heterogeneous Cu nanoparticles in NaOH solution was studiedin a microreactor by a CFD simulation. A seven-inlet micromixer comprising an optimized mixing unitwas incorporated for uniform distribution of the species. The effects of various parameters upon the processperformance were considered and the optimum points were determined. Also, the extent of theinfluence of each variable on LA yield was evaluated using sensitivity analysis techniques. While higherLA yield could be obtained at extreme scenarios, optimum values of the Re and temperature for obtainingthe maximum performance under sensible operating conditions were determined to be 0.108 and 510.1 Kwhich led to the optimum yields of 67.8% and 59.5%, respectively. Moreover, the sensitivity analysisrevealed that the molar ratio of OH /GLY and temperature were the most and least significant parameters,respectively.

The Effect of Nurses’ Participation in Management (by Suggestions System)on their Quality of Work Life

Hosseini. M. A.,Javadpoor, H,Sadjadi, S. 한국간호과학회 2009 한국간호과학회 학술대회 Vol.2009 No.10