Mixture rule for studding the environmental pollution reduction in concrete structures containing nanoparticles

Tabatabaei, Javad,Nourbakhsh, Seyed Hesam,Siahkar, Mahdi Techno-Press 2020 Coupled systems mechanics Vol.9 No.3

Nanotechnology is an upcoming technology that can provide solution for combating pollution by controlling shape and size of materials at the nanoscale. This review provides comprehensive information regarding the role of nanotechnology in pollution control at concrete structures. Titanium dioxide (TiO2) nanoparticles are a good item for concrete structures for diminishing the air polluting affect by gasses of exhaust. In this article, the mixture rule is presented for the effect of nanoparticles in environmental pollution reduction in concrete structures. The compressive strength, elastic modulus and reduction of steel bars in the concrete structures are studied. The Results show that TiO2 nanoparticles have significant effect on the reduction of environmental pollution and increase of stiffness in the concrete structures. In addition, the nanoparticles can reduce the use of steel bars in the concrete structure.

Large strain analysis of two-dimensional frames by the normal flow algorithm

Tabatabaei, R.,Saffari, H 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.5

Nonlinear equations of structures are generally solved numerically by the iterative solution of linear equations. However, this iterative procedure diverges when the tangent stiffness is ill-conditioned which occurs near limit points. In other words, a major challenge with simple iterative methods is failure caused by a singular or near singular Jacobian matrix. In this paper, using the Newton-Raphson algorithm based on Davidenko’s equations, the iterations can traverse the limit point without difficulty. It is argued that the propose algorithm may be both more computationally efficient and more robust compared to the other algorithm when tracing path through severe nonlinearities such as those associated with structural collapse. Two frames are analyzed using the proposed algorithm and the results are compared with the previous methods. The ability of the proposed method, particularly for tracing the limit points, is demonstrated by those numerical examples.

Pyruvate Dehydrogenase Complex and Glucose Oxidation as a Therapeutic Target in Diabetic Heart Disease

Tabatabaei Dakhili Seyed Amirhossein,Amanda A. Greenwell,John R. Ussher 한국지질동맥경화학회 2023 지질·동맥경화학회지 Vol.12 No.1

Diabetic cardiomyopathy was originally described as the presence of ventricular dysfunction in the absence of coronary artery disease and/or hypertension. It is characterized by diastolic dysfunction and is more prevalent in people with diabetes than originally realized, leading to the suggestion in the field that it simply be referred to as diabetic heart disease. While there are currently no approved therapies for diabetic heart disease, a multitude of studies clearly demonstrate that it is characterized by several disturbances in myocardial energy metabolism. One of the most prominent changes in myocardial energy metabolism in diabetes is a robust impairment in glucose oxidation. Herein we will describe the mechanisms responsible for the diabetes-induced decline in myocardial glucose oxidation, and the pharmacological approaches that have been pursued to correct this metabolic disorder. With surmounting evidence that stimulating myocardial glucose oxidation can alleviate diastolic dysfunction and other pathologies associated with diabetic heart disease, this may also represent a novel strategy for decreasing the prevalence of heart failure with preserved ejection fraction in the diabetic population.

Influence of near-fault ground motions characteristics on elastic seismic response of asymmetric buildings

Tabatabaei, R.,Saffari, H. Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.4

The elastic seismic response of plan-asymmetric multi storey steel-frame buildings is investigated under earthquake loading with particular emphasis on forward-rupture directivity and fling records. Three asymmetric building systems are generated with different torsional stiffness and varying static eccentricity. The structural characteristic of these systems are designed according to UBC 97 code and their seismic responses subjected to a set of earthquake records are obtained from the response history analysis (RHA) as well as the linear static analysis (LSA). It is shown that, the elastic torsional response is influenced by the intensity of near-fault ground motions with different energy contents. In the extreme case of very strong earthquakes, the behaviour of torsionally stiff buildings and torsionally flexible buildings may differ substantially due to the fact that the displacement envelope of the deck depends on ground motion characteristics.

PLGA-Based Nanoparticles as Cancer Drug Delivery Systems

Tabatabaei Mirakabad, Fatemeh Sadat,Nejati-Koshki, Kazem,Akbarzadeh, Abolfazl,Yamchi, Mohammad Rahmati,Milani, Mortaza,Zarghami, Nosratollah,Zeighamian, Vahideh,Rahimzadeh, Amirbahman,Alimohammadi, So Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Poly (lactic-co-glycolic acid) (PLGA) is one of the most effective biodegradable polymeric nanoparticles (NPs). It has been approved by the US FDA to use in drug delivery systems due to controlled and sustained-release properties, low toxicity, and biocompatibility with tissue and cells. In the present review, the structure and properties of PLGA copolymers synthesized by ring-opening polymerization of DL-lactide and glicolide were characterized using 1H nuclear magnetic resonance spectroscopy, gel permeation chromatography, Fourier transform infrared spectroscopy and differential scanning calorimetry. Methods of preparation and characterization, various surface modifications, encapsulation of diverse anticancer drugs, active or passive tumor targeting and different release mechanisms of PLGA nanoparticles are discussed. Increasing experience in the application of PLGA nanoparticles has provided a promising future for use of these nanoparticles in cancer treatment, with high efficacy and few side effects.

The effect of TiO2 nanoparticles in reduction of environmental pollution in concrete structures

Tabatabaei, Javad,Gorji, Leila Techno-Press 2019 Advances in concrete construction Vol.7 No.2

Heterogeneous photocatalysis is developed rapidly in the field of engineering of environmental. It has a good potential to tackle with the enhancing traffic pollution. Adding photocatalyst to usual building materials such as cement and concrete makes friendly environmental materials against the air pollution. TiO2 nanoparticles are a good item for concrete structures for diminishing the air polluting affect by gasses of exhaust. In specific, the transformation of NOx to NO3- is studied and the interaction of TiO2 nanoparticles and concrete is investigated here by experimental test. This paper presents an overview of the principle of photocatalysis and the application in combination with cement, as well as the results of the laboratory research, especially towards air purifying action. In addition, by the analytical models, the influence of TiO2 nanoparticles is studied on the stiffness of the concrete. The Results show that TiO2 nanoparticles have significant effect on the reduction of environmental pollution and increase of stiffness in the concrete structures.

Demonstration of Torsional Behaviour Using Vibration-based Single-storey Model with Double Eccentricities

R. Tabatabaei,H. Saffari 대한토목학회 2010 KSCE JOURNAL OF CIVIL ENGINEERING Vol.14 No.4

The use of single-storey schemes appears necessary in order to investigate lateral-torsional coupling in building structures. In this paper, the torsional behaviour of an eccentric single-storey system based on undamped free vibration analysis has been investigated with particular emphasis on double eccentricities. An eccentricity between the center of rigidity and the center of mass in a building system causes the different torsional behaviour during a seismic loading. This approach reveals clearly how the double eccentric system behaves in relationship with the natural frequencies and modes and translational or torsional motion of the modeling system. From the parametric analysis of such an approach the determinative role of the distance from the center of mass to the center of rotation corresponding to the torsional and lateral stiffness ratio of the system becomes an obvious means of defining the torsional behaviour. From the outcome of applying the model, the building model can be classified as Torsionally Stiff (TS) and Torsionally Flexible (TF) based on the way the model has been configured in terms of the loci of the centers of rotation.

CRA based control of fractional order systems subject to control signal constraint

Mohammad Tabatabaei,Mohammad Haeri 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

An approach is proposed to control transient response of fractional order systems with maximum permissible control signal. This goal is achieved using a newly suggested characteristic ratio assignment method. Based on the proposed method, the generalized time constant τ and the characteristic ratios including their pattern, an adjustable parameter β , and the product of two successive characteristic ratios ρ are determined such that predefined level of overshoot and time specification of closed loop step response are obtained while the control signal is confined to a pre assigned maximum magnitude. The raised issue is solved by defining an optimization problem in which the design parameters are τ , β , and ρ. Numerical simulations results are provided to illustrated performance of the proposed method.

Influence of near-fault ground motions characteristics on elastic seismic response of asymmetric buildings

R. Tabatabaei,H. Saffari 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.4

The elastic seismic response of plan-asymmetric multi storey steel-frame buildings is investigated under earthquake loading with particular emphasis on forward-rupture directivity and fling records. Three asymmetric building systems are generated with different torsional stiffness and varying static eccentricity. The structural characteristic of these systems are designed according to UBC 97 code and their seismic responses subjected to a set of earthquake records are obtained from the response history analysis (RHA) as well as the linear static analysis (LSA). It is shown that, the elastic torsional response is influenced by the intensity of near-fault ground motions with different energy contents. In the extreme case of very strong earthquakes, the behaviour of torsionally stiff buildings and torsionally flexible buildings may differ substantially due to the fact that the displacement envelope of the deck depends on ground motion characteristics.

The use of artificial neural networks in predicting ASR of concrete containing nano-silica

Ramin Tabatabaei,Hamid Reza Sanjari,Mohsen Shamsadini 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.13 No.6

In this article, by using experimental studies and artificial neural network has been tried to investigate the use of nano-silica as concrete admixture to reduce alkali-silica reaction. If there are reactive aggregates and alkali of cement with enough moisture in concrete, a gel will be formed. Then with high reactivity between alkali of cement and existence of silica in aggregates, this gel will expand by absorption of water, and causes expansive pressure and cracks be formed. At the time passes, this gel will reduce bothdurability and strength of the concrete. By reducing the size of silicate to nano, specific surface area of particles and number of atoms on the surface will be increased, which causes more pozzolanic activity of them. Nano-silica can react with calcium hydroxide (Ca (OH)2) and produces C-S-H gel. In this study,accelerated mortar bar specimens according to ASTM C 1260 and ASTM C 1567, with different mix proportions were prepared using aggregates of Kerman, such as: none admixture and plasticizer, differentproportions of nano-silica separately. By opening the moulds after 24 hour and curing in water at 80 °C for 24 hour, then curing in (1N NaOH) at 80 °C for 14 days, length expansion of mortar bars were measured and compared. It was noted that, the lowest length expansion of a specimens shows the best proportion of admixture based on alkali-silica reactivity. Then, prediction of alkali-silica reaction of concrete has been investigated by using artificial neural network. In this study the backpropagation network has been used and compared with different algorithms to train network. Finally, the best amount of nano silica for adding to mix proportion, also the best algorithm and number of neurons in hidden layer of artificial neural network have been offered.