An Artificial Neural Networks Model for Predicting Permeability Properties of Nano Silica–Rice Husk Ash Ternary Blended Concrete

Alireza Najigivi,Alireza Khaloo,Azam Iraji zad,Suraya Abdul Rashid 한국콘크리트학회 2013 International Journal of Concrete Structures and M Vol.7 No.3

In this study, a two-layer feed-forward neural network was constructed and applied to determine a mapping associating mix design and testing factors of cement?nano silica (NS)?rice husk ash ternary blended concrete samples with their performance in conductance to the water absorption properties. To generate data for the neural network model (NNM), a total of 174 field cores from 58 different mixes at three ages were tested in the laboratory for each of percentage, velocity and coefficient of water absorption and mix volumetric properties. The significant factors (six items) that affect the permeability properties of ternary blended concrete were identified by experimental studies which were: (1) percentage of cement; (2) content of rice husk ash; (3) percentage of 15 nm of SiO₂ particles; (4) content of NS particles with average size of 80 nm; (5) effect of curing medium and (6) curing time. The mentioned significant factors were then used to define the domain of a neural network which was trained based on the Levenberg?Marquardt back propagation algorithm using Matlab software. Excellent agreement was observed between simulation and laboratory data. It is believed that the novel developed NNM with three outputs will be a useful tool in the study of the permeability properties of ternary blended concrete and its maintenance.

Experimentally evaluating the seismic retrofitting of square engineered cementitious composite columns using CFRP

Alireza Akhtari,Alireza Mortezaei,Ali Hemmati 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.78 No.5

The present experimental study evaluated the seismic performance of six engineered cementitious composite (ECC) columns strengthened with carbon fiber reinforced polymer (CFRP) laminates under cyclic lateral loading. The ECC columns damaged and crushed in the first stage of cyclic tests were repaired using the ECC with a certain polyvinyl alcohol (PVA) fiber and strengthened with flexural and sheer CFRP laminates and then re-assessed under the cyclic loading. The effects of some variables were examined on lateral displacement, energy absorption and dissipation, failure modes, crack patterns, load bearing capacity and plasticity, and the obtained results were compared with those of the first stage of cyclic tests. The results showed that retrofitting the ECC columns can improve their performance, plasticity and load-bearing threshold, delayed the concrete failure, changed the failure modes and increased the energy absorbed by the strengthened columns element by over 50%.

Outcome of open reduction and Kirschner wire fixation in pediatric radial neck fracture

Alireza Rouhani,Mohammadreza Chavoshi,Alireza Sadeghpour,Hossein Aslani,Mohsen Mardani-Kivi 대한견주관절의학회 2021 대한견주관절의학회지 Vol.24 No.4

Background: Radial neck fracture in children is rare. This study attempted to evaluate the outcome of surgically treated patients and any associated complications. Methods: This study evaluated 23 children under 15 years of age with radial neck fracture who were treated with open reduction between 2006 and 2016 to determine their range of motion, postoperative complications, and radiographic outcomes. The results were assessed clinically using the Mayo clinic elbow performance score. Results: The mean follow-up duration for patients was 34.6 months. The average postoperative angulation was 3.6°. Hypoesthesia was reported in only 9% of patients, and none of the patients complained of postoperative pain. The postoperative X-ray results were excellent in 60% and good in 40%. No radiographic complications were identified. The elbow score was excellent in 87% and good in 13% (mean score, 96.74). There was a statistical relationship between range of motion limitations and age, degree of fracture, initial displacement, and surgical pin removal time. Conclusions: Although most patients accept the closed reduction method as a primary treatment, the present study suggests that an open-reduction approach has been associated with optimal therapeutic outcomes for patients in whom closed reduction was not satisfactory or indicated.

Applying SVM framework for modeling of CO₂ solubility in oil during CO₂ flooding

Rostami, Alireza,Arabloo, Milad,Lee, Moonyong,Bahadori, Alireza Elsevier 2018 Fuel Vol.214 No.-

<P><B>Abstract</B></P> <P>CO<SUB>2</SUB> solubility is one of the most important parameters that affects CO<SUB>2</SUB> flooding, because gas dissolution into crude oil results in oil swelling, viscosity reduction, IFT reduction, oil mobilization, and oil recovery improvement. Therefore, a better understanding of CO<SUB>2</SUB> solubility mechanisms and its influence on physical properties of crude oil are essential to any effective CO<SUB>2</SUB> flooding process. In this study, Least-Square Support Vector Machine (LSSVM) as a newly established soft computing algorithm is applied for developing a new correlative model for CO<SUB>2</SUB> solubility in both dead and live oil systems. CO<SUB>2</SUB> solubility in dead oil is basically affected by the oil saturation pressure (P<SUB>s</SUB>), oil specific gravity (<I>γ</I>), oil molecular weight (MW), and reservoir temperature (T). Moreover, the impact of bubble point pressure is considered in constructing the LSSVM model for the live oil. A number of statistical quality measures are utilized to assess and demonstrate the superior capability of the newly developed LSSVM model in comparison with the previous empirically derived correlations. The average absolute relative deviation (AARD) and coefficient of determination (R<SUP>2</SUP>) of 2.2783% and 0.9933 for the dead oil system, and 1.7432% and 0.9958 for the live oil system, respectively, verify the acceptable accuracy and efficient performance of the proposed LSSVM model over a wide range of dataset used in this study within the range of the used databank. However, the impact of CO<SUB>2</SUB> liquefaction pressure is ignored, the LSSVM model gives the best result. In conclusion, it is worth mentioning that the proposed LSSVM model can serve as an accurate correlative tool for fast and effective estimation of CO<SUB>2</SUB> solubility in both dead and live crude oils.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new soft computing model is established for CO<SUB>2</SUB> solubility prediction in both dead and live oil systems. </LI> <LI> Several statistical parameters are utilized to demonstrate the superiority of the suggested SVM model. </LI> <LI> The performance of the developed model is compared with other literature correlations. </LI> <LI> The proposed model can serve as accurate tool for effective estimation of CO<SUB>2</SUB>-crude oil solubility. </LI> <LI> The impact of all input variables on the target values based on different techniques is determined. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Theoretical Studies of Hydrogen Bond Interactions in 4-Substituted Benzoic Acids Dimers

Beni, Alireza Salimi,Chermahini, Alireza Najafi,Sharghi, Hashem Korean Chemical Society 2011 대한화학회지 Vol.55 No.3

벤조산 유도체($NH_2$, OH, H, F, Cl, CN, NO, $NO_2$) 의 두 형태를 6-311++G(d,p) 바탕 집합을 이용하여 MP2, DFT 및 HF 수준으로 연구하였으며, cis이성 질체가 더 안정하였다. 벤조산의 수소 결합 형성은 안정화 에너지를 이용하여 추산하였으며, 이합체에 대한 수소결합 에너지 계산치는 고리에서 협동 상호작용이 일어남을 보여주었다. 페닐 고리로 전자를 밀어내는 그룹(ERG)은 더 안정한 수소 결합이 형성하였다. 이합체에서 O-H 결합의 적색이동은 -565.3에서 $-589.3\;cm^{-1}$ 범위였으며, 상호 작용의 특성은 NBO 분석을 이용하여 연구하였다. Two conformations of benzoic acid derivatives ($NH_2$, OH, H, F, Cl, CN, NO, $NO_2$) have been investigated at MP2, DFT and HF level using the 6-311++G(d,p) basis set. It was found that the cis isomers are more stable. Hydrogen bonding formation of benzoic acids has been estimated from stabilization energies. The calculated hydrogen-bonding energies of dimers showed a cooperative interaction in the cyclic ones. It was found that an electron-releasing group (ERG) into the phenyl rings resulted in the formation of more stable hydrogen bonding. Red shift of O-H bond was found from -565.3 to -589.3 for dimers. The natural bond orbital (NBO) analysis was applied to characterize nature of the interaction.

Vibration analysis of non-uniform tapered beams with nonlinear FGM properties

Alireza Keshmiri,Nan Wu,Quan Wang 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.11

This paper presents the free vibration analysis of a non-uniform cone beam with nonlinearly varying axial functionally graded material (FGM) properties. Based on the Adomian decomposition method and a proposed modified mathematical procedure, the vibration mode shapes and natural frequencies of a nonlinearly tapered FGM beam are analytically derived. Several vibration analyses for uniform and non-uniform FGM structures are presented and the results are compared with the existing ones to prove the effectiveness and accuracy of the proposed methodology. Additionally, vibration analysis of exponentially and trigonometrically tapered beams with nonlinearly axial varying FGM properties considering different geometry and material taper ratios was studied and presented. Based on this analytical model, ideal structural design can be efficiently achieved for many engineering applications, such as stability enhancement and energy harvesting.

Comparative Study of Research Article Discussion Sections of Local and International Applied Linguistic Journals

Alireza Jalilifar,A. M. Hayati,Namdar Namdari 아시아영어교육학회 2012 The Journal of Asia TEFL Vol.9 No.1

Seismic Behavior Investigation of the Corrugated Steel Shear Walls Considering Variations of Corrugation Geometrical Characteristics

Alireza Farzampour,Iman Mansouri,허종완 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.4

The corrugated steel plate shear walls have recently been proposed to address the seismic issues associated with simple steel plate shear walls; however, stiff ness, strength, and ductility of the corrugated shear walls are signifi cantly aff ected by varying the corrugation geometry under seismic loading. The present study investigates steel shear walls’ models with corrugated or simple infi ll plates subjected to monotonic and cyclic loads. The performance of the corrugated steel plate is evaluated and then compared to that of the simple steel plates by evaluating the damping ratios and energy dissipation capability. The eff ect of corrugation profi le angle, the existence of an opening, and the corrugation subpanel length are numerically investigated after validation of the fi nite element modeling methodology. The results demonstrate that incorporating corrugated plates would lead to better seismic damping ratios, specifi cally in the case of opening existence inside of the infi ll plate. Specifi cally, the corrugation angle of 30° decreases the ultimate strength, while increasing the initial stiff ness and ductility. In addition, the subpanel length of 100 mm is found to be able to improve the overall performance of shear wall by providing each subpanel appropriate support for the adjacent subpanel, leading to a suffi cient buckling resistance performance.

Confinement effect on the behavior factor of dual reinforced concrete moment-resisting systems with shear walls

Alireza Habibi,Mehdi Izadpanah,Yaser Rahmani 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.85 No.6

Lateral pressure plays a significant role in the stress-strain relationship of compressed concrete. Concrete’s internal cracking resistance, ultimate strain, and axial strength are improved by confinement. This phenomenon influences the nonlinear behavior of reinforced concrete columns. Utilizing behavior factors to predict the nonlinear seismic responses of structures is prevalent in seismic codes, and this factor plays a vital role in the seismic responses of structures. This study aims to evaluate the confining action on the behavior factor of reinforced concrete moment resisting frames (RCMRFs) with shear walls (SWRCMRFs). To this end, a diverse range of mid-rise SW-RCMRFs was initially designed based on the Iranian national building code criteria. Second, the stress-strain curve of each element was modeled twice, both with and without the confinement phenomenon. Each frame was then subjected to pushover analysis. Finally, the analytical behavior factors of these frames were computed and compared to the Iranian seismic code behavior factor. The results demonstrate that confining action increased the behavior factors of SW-RCMRFs by 7-12%.

The Role of Athletic Tourism in Economic Evolution and Sustainable Development in Rudbar-e Ghasran Village

( Alireza Jalalzaei ) 세계문화관광학회 2014 International Journal of Culture and tourism Resea Vol.7 No.1

The increasing environmental evolution, social life, technology, transportation and subsistence of human relief times cause to appearance of tourism as animportant economic and social category in the world. The main aim of this study is requirement to recognition of tourism potencies and deficiencies in this zone and proposing of guidelines and strategies for development and increasing of tourism level in future. In order to study the desirable and unfavorable factors of athletic tourism and their guidelines and precedence’s proposition in studied region by analysis method SWOT and their precedence by quantitative matrix QSPM. The results obtaining questionnaire processing and used methods showed that among the internal factors, type and climate of village influence in region tourism. From the guidelines point of view, Rudbare-e Ghasran village was not proper situation. The rank of many factors is low and this problem have influenced in values of total factors. The final priority of guidelines also showed that different guidelines exist among top guidelines because requirement of region to adopt of varied policies. Generally, as a final conclusion can be said that Rudbar-e Ghasran village process varied funds of athletic tourism but face with many problems in fields of facilities and tourist attraction. Therefore, was not in a good situation strategically, so the major of used guidelines should be of opportunity and abilities utilization that would cause to growth and athletic tourism development in Rudbare-e Ghasran village in future.