Kharazmi University

About: Kharazmi University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Membrane & Supply chain. The organization has 3395 authors who have published 5321 publications receiving 45645 citations. The organization is also known as: Tarbiat Moallem University of Tehran & Teacher Training University.

Effect of vertical component of an earthquake on steel frames considering soil-structure interaction

Abstract: The present study investigated the effects of vertical components of earthquakes on the responses of 5, 15, and 25 story steel frames by taking into account Soil-Structure Interaction (SSI). The frames were modeled on a fixed base and simulated using two shear waves velocities for the soil (100 and 250 m/s according to NEHERP soil code types E and D soils) using a cone model. The nonlinear behavior of the frames was investigated in the presence and absence of the vertical component of an earthquake and the effects of SSI were examined by comparing the results of the latter analysis with and without use of the cone model. The results showed that the vertical component and SSI can increase the axial force on columns by nearly 50%, the vertical displacement of the mid-point of the beams by nearly two-fold, drift of the stories by nearly 40%, and foundation rotation. Story shear was less affected. When soil type E and soil type D were compared, it was found that the effect of the vertical component of earthquakes on the dynamic response of the frames was generally significant.

School Travel Mode Use: Direct and Indirect Effects through Attitudes and Transport Priorities

Abstract: Considering both direct and indirect associations, this study investigated a structural framework linking social cognition latent variables, and socioeconomic, built environment and demographic cha...

A digoxin electrochemical aptasensor using Ag nanoparticle decorated graphene oxide

Abstract: In this work, a highly sensitive aptasensor for digoxin determination in biological samples has been introduced. The surface of a gold screen-printed electrode was modified by using electrodeposited gold nanoparticles (GNPs). A monolayer of 3-mercaptopropionic acid (MPA) was then self-assembled on the GNP surfaces. Subsequently, an amino-labeled digoxin specific aptamer was covalently bonded to the carboxylic groups of MPA on the GNPs through imide bond formation. The silver nanoparticle decorated graphene oxide (AgNPs–GO) interacted with the immobilized aptamer via π–π interaction and the oxidation signal of AgNPs was monitored. In the presence of digoxin, the hybrid left the electrode surface due to the specific interaction between the aptamer and digoxin, and the oxidation signal decreased. The proposed aptasensor delivered a linear dynamic range of 1 pM to 0.1 μM and a detection limit of 0.3 pM and was successfully utilized for digoxin determination in biological samples with good reliability.