Strengthening of the panel zone in steel moment-resisting frames

Abedini, Masoud,Raman, Sudharshan N.,Mutalib, Azrul A.,Akhlaghi, Ebrahim Techno-Press 2019 Advances in computational design Vol.4 No.4

Rehabilitation and retrofitting of structures designed in accordance to standard design codes is an essential practice in structural engineering and design. For steel structures, one of the challenges is to strengthen the panel zone as well as its analysis in moment-resisting frames. In this research, investigations were undertaken to analyze the influence of the panel zone in the response of structural frames through a computational approach using ETABS software. Moment-resisting frames of six stories were studied in supposition of real panel zone, different values of rigid zone factor, different thickness of double plates, and both double plates and rigid zone factor together. The frames were analyzed, designed and validated in accordance to Iranian steel building code. The results of drift values for six stories building models were plotted. After verifying and comparing the results, the findings showed that the rigidity lead to reduction in drifts of frames and also as a result, lower rigidity will be used for high rise building and higher rigidity will be used for low rise building. In frames with story drifts more than the permitted rate, where the frames are considered as the weaker panel zone area, the story drifts can be limited by strengthening the panel zone with double plates. It should be noted that higher thickness of double plates and higher rigidity of panel zone will result in enhancement of the non-linear deformation rates in beam elements. The resulting deformations of the panel zone due to this modification can have significant influence on the elastic and inelastic behavior of the frames.

The Effects of Auriculotherapy on Shoulder Pain After a Cesarean Section

Abedini Maryam,Manshoori Azita,Bakhtar Babak,Aminzadeh Fariba,Sadeghi Tabandeh 사단법인약침학회 2020 Journal of Acupuncture & Meridian Studies Vol.13 No.5

Background: Postcesarean section shoulder pain caused by constrained upper extremity movement limits the maternal activities of breastfeeding and neonatal care. Objectives: This study aims at investigating the effects of auriculotherapy on shoulder pain after a cesarean section. Methods: In this randomized controlled trial, 90 candidates for a cesarean section were selected according to the inclusion and exclusion criteria and randomly allocated into control and intervention groups by the minimization method. In the intervention group, ear seeds were placed on shoulder and muscle relaxation points from two hours prior to surgery until 24 hours after it. In the control group, ear seeds were placed on placebo points. Shoulder pain was assessed on a numerical pain scale in 1, 6, and 24 hours after surgery. Results: There was no significant difference between the two groups 1 and 6 hours after surgery. However, there was a significant difference between the two groups 24 hours after surgery and the mean pain score was lower in the intervention group (independent t-test, p < 0.001). Conclusion: The use of auriculotherapy is recommended for the prevention and alleviation of shoulder pain after a cesarean section.

Akt promotes chemoresistance in human ovarian cancer cells by modulating cisplatin-induced, p53-dependent ubiquitination of FLICE-like inhibitory protein

Abedini, M R,Muller, E J,Bergeron, R,Gray, D A,Tsang, B K Macmillan Publishers Limited 2010 Oncogene Vol.29 No.1

Although Akt is a determinant of cisplatin (cis-diaminedichloroplatinum (CDDP)) resistance in ovarian cancer cells, which is related in part to its inhibitory action on p53 activation, precisely how Akt confers CDDP resistance is unclear. In this study, we show that CDDP induced p53-dependent Fas-associated death domain-like interleukin-1β-converting enzyme (FLICE)-like inhibitory protein (FLIP) degradation in chemosensitive ovarian cancer cells but not their resistant counterparts. CDDP induced FLIP–p53–Itch interaction, colocalization and FLIP ubiquitination in chemosensitive but not chemoresistant ovarian cancer cells. Moreover, although activated Akt inhibited CDDP-induced FLIP degradation and apoptosis in sensitive cells, these responses were facilitated by dominant-negative Akt expression in chemoresistant cells. Inhibition of Akt function also facilitated p53–FLIP interaction and FLIP ubiquitination, which were attenuated by p53 silencing. These results suggest that Akt confers resistance, in part, by modulating CDDP-induced, p53-dependent FLIP ubiquitination. Understanding the precise etiology of chemoresistance may improve treatment for ovarian cancer.

The Greater Arab Free Trade Area(GAFTA): an Estimation of Its Trade Effects

( Javad Abedini ),( Nicolas Peridy ) 세종대학교 경제통합연구소 (구 세종대학교 국제경제연구소) 2008 Journal of Economic Integration Vol.23 No.4

In 1997, fourteen Arab countries concluded an agreement, aimed at achieving the Greater Arab Free Trade Area (GAFTA) by 1.1.2007 at the latest. This paper provides a first ex-post appraisal of the GAFTA agreement`s trade effects. Based on new theoretical developments of the gravity equation, we estimate a panel data model which covers trade within the GAFTA area as well as with 35 other reference countries, over the period 1988-2005. Several estimators are presented, especially transformed fixed-effects, Hausman and Taylor as well as a GMM dynamic estimator. As a main finding, the calculation of gross trade creation shows that regional trade has increased by 20% since GAFTA has been implemented.

Residual capacity assessment of post-damaged RC columns exposed to high strain rate loading

Masoud Abedini,Chunwei Zhang 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.3

Residual capacity is defined as the load carrying capacity of an RC column after undergoing severe damage. Evaluation of residual capacity of RC columns is necessary to avoid damage initiation in RC structures. The central aspect of the current research is to propose an empirical formula to estimate the residual capacity of RC columns after undergoing severe damage. This formula facilitates decision making of whether a replacement or a repair of the damaged column is adequate for further use. Available literature mainly focused on the simulation of explosion loads by using simplified pressure time histories to develop residual capacity of RC columns and rarely simulated the actual explosive. Therefore, there is a gap in the literature concerning general relation between blast damage of columns with different explosive loading conditions for a reliable and quick evaluation of column behavior subjected to blast loading. In this paper, the Arbitrary Lagrangian Eulerian (ALE) technique is implemented to simulate high fidelity blast pressure propagations. LS-DYNA software is utilized to solve the finite element (FE) model. The FE model is validated against the practical blast tests, and outcomes are in good agreement with test results. Multivariate linear regression (MLR) method is utilized to derive an analytical formula. The analytical formula predicts the residual capacity of RC columns as functions of structural element parameters. Based on intensive numerical simulation data, it is found that column depth, longitudinal reinforcement ratio, concrete strength and column width have significant effects on the residual axial load carrying capacity of reinforced concrete column under blast loads. Increasing column depth and longitudinal reinforcement ratio that provides better confinement to concrete are very effective in the residual capacity of RC column subjected to blast loads. Data obtained with this study can broaden the knowledge of structural response to blast and improve FE models to simulate the blast performance of concrete structures.

Effect of calcination temperature on the particle sizes of zinc ferrite prepared by a combination of sol-gel auto combustion and ultrasonic irradiation techniques

S. Abedini Khorrami,G. Mahmoudzadeh,S. S. Madani,F. Gharib 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.5

ZnFe2O4 nanocrystallites were synthesized successfully by a combination of sol-gel auto combustion and ultrasonic irradiation techniques. The influence of the calcination temperature on the particle sizes was investigated. The particles have been calcined at temperatures varying from 400 to 900 oC. The studies were carried out using XRD and SEM techniques. The gradual increase in the crystallite size with the calcination temperature indicates the formation of bigger particles by the calcination.

Dynamic vulnerability assessment and damage prediction of RC columns subjected to severe impulsive loading

Masoud Abedini,Chunwei Zhang 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.4

Reinforced concrete (RC) columns are crucial in building structures and they are of higher vulnerability to terrorist threat than any other structural elements. Thus it is of great interest and necessity to achieve a comprehensive understanding of the possible responses of RC columns when exposed to high intensive blast loads. The primary objective of this study is to derive analytical formulas to assess vulnerability of RC columns using an advanced numerical modelling approach. This investigation is necessary as the effect of blast loads would be minimal to the RC structure if the explosive charge is located at the safe standoff distance from the main columns in the building and therefore minimizes the chance of disastrous collapse of the RC columns. In the current research, finite element model is developed for RC columns using LS-DYNA program that includes a comprehensive discussion of the material models, element formulation, boundary condition and loading methods. Numerical model is validated to aid in the study of RC column testing against the explosion field test results. Residual capacity of RC column is selected as damage criteria. Intensive investigations using Arbitrary Lagrangian Eulerian (ALE) methodology are then implemented to evaluate the influence of scaled distance, column dimension, concrete and steel reinforcement properties and axial load index on the vulnerability of RC columns. The generated empirical formulae can be used by the designers to predict a damage degree of new column design when consider explosive loads. With an extensive knowledge on the vulnerability assessment of RC structures under blast explosion, advancement to the convention design of structural elements can be achieved to improve the column survivability, while reducing the lethality of explosive attack and in turn providing a safer environment for the public.

An Efficient and Chemoselective Method for Synthesis of 1,3-Oxathiolanes from Aldehydes and their Deprotection Catalyzed by V(HSO₄)₃

Shirini, F.,Abedini, M.,Ghasemi, M.,Sakhaei, A.R. Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.10

Application of Lagrangian approach to generate P-I diagrams for RC columns exposed to extreme dynamic loading

Zhang, Chunwei,Abedini, Masoud Techno-Press 2022 Advances in concrete construction Vol.14 No.3

The interaction between blast load and structures, as well as the interaction among structural members may well affect the structural response and damages. Therefore, it is necessary to analyse more realistic reinforced concrete structures in order to gain an extensive knowledge on the possible structural response under blast load effect. Among all the civilian structures, columns are considered to be the most vulnerable to terrorist threat and hence detailed investigation in the dynamic response of these structures is essential. Therefore, current research examines the effect of blast loads on the reinforced concrete columns via development of Pressure- Impulse (P-I) diagrams. In the finite element analysis, the level of damage on each of the aforementioned RC column will be assessed and the response of the RC columns when subjected to explosive loads will also be identified. Numerical models carried out using LS-DYNA were compared with experimental results. It was shown that the model yields a reliable prediction of damage on all RC columns. Validation study is conducted based on the experimental test to investigate the accuracy of finite element models to represent the behaviour of the models. The blast load application in the current research is determined based on the Lagrangian approach. To develop the designated P-I curves, damage assessment criteria are used based on the residual capacity of column. Intensive investigations are implemented to assess the effect of column dimension, concrete and steel properties and reinforcement ratio on the P-I diagram of RC columns. The produced P-I models can be applied by designers to predict the damage of new columns and to assess existing columns subjected to different blast load conditions.

Trade Effects of Regional Integration in Imperfect Competition: Evidence from the Greater Arab Free Trade Area (GAFTA)

Nicolas Peridy,Javad Abedini 한국국제경제학회 2014 International Economic Journal Vol.28 No.2

This article aims to provide new insights into trade effects of the Greater Arab Free Trade Area (GAFTA), using an imperfect competition framework. The model combines the new gravity model approach with supply-demand export equations in imperfect competition. In this regard, the role of scale economies, product varieties and expectations is explored. Facing the lack of international data on scale economies, we also develop a translog production system which makes it possible to obtain reliable estimates of this factor. For a more rigorous treatment of the endogeneity problem in the model, we make use of an instrumental GMM panel estimator. Results show limited effects of GAFTA on regional trade in imperfect competition, due to market segmentation and the predominance of inter-industry trade. In addition, the fitted intra-GAFTA trade values are far beyond the actual ones. This suggests that GAFTA countries could benefit from deeper regional trade integration. In this regard, the Arab Spring creates new opportunities to reinforce trade integration as a means of grasping additional trade gains in this area.