Tetrahydrofuran vapour sensing by electrically conductive silver nanoparticle doped Poly-1-napthylamine-titanium(IV)sulphosalicylophosphate ion exchange nanocomposite

Rizwan Hussain,Mohd Quasim Khan,Asif Ali Khan 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.70 No.-

A novel Poly-1-napthylamine-titanium(IV)sulphosalicylophosphate (PNA-TSP) cation exchange nanocompositewas synthesized by in-situ chemical oxidative polymerization of 1-naphthylamine in thepresence of titanium(IV)sulphosalicylophosphate (TSP) nanoparticles. PNA-TSP doped with silvernanoparticles was synthesized by chemical reduction method. Synthesis of PNA-TSP and Ag/PNA-TSP wasconfirmed by FTIR, FE-SEM, XRD, TGA and EDX characterization techniques. Nanocomposite showedgood ion-exchange capacity (IEC) (2.20 meq g 1) and enhanced DC electrical conductivity from 0.163 S/cm (PNA-TSP) to 0.7112 S/cm (Ag/PNA-TSP). Ag/PNA-TSP nanocomposite based sensor was fabricated forthe detection of tetrahydrofuran vapours over the concentration range from 0.1 M (vapour concentration2.90%) to 0.7 M (vapour concentration 4.24%) tetrahydrofuran solution.

Enhanced Classical Tafel Diagram Model for Corrosion of Steel in Chloride Contaminated Concrete and the Experimental Non-Linear Effect of Temperature

Hussain, Raja Rizwan Korea Concrete Institute 2010 International Journal of Concrete Structures and M Vol.4 No.2

The chloride ion attack on the passive iron oxide layer of reinforcement steel embedded in concrete under variable temperature environment is influenced by several parameters and some of them still need to be further investigated in more detail. Different school of thoughts exist between past researchers and the data is limited in the high temperature and high chloride concentration range which is necessary with regards to setting boundary conditions for enhancement of tafel diagram model presented in this research. The objective of this paper is to investigate the detrimental coupled effects of chloride and temperature on corrosion of reinforced concrete structures in the high range by incorporating classical Tafel diagram chloride induced corrosion model and laboratory controlled experimental non-linear effect of temperature on corrosion of rebar embedded in concrete.

Investigation of Volumetric Effect of Coarse Aggregate on Corroding Steel Reinforcement at the Interfacial Transition Zone of Concrete

Raja Rizwan Hussain,Tetsuya Ishida 대한토목학회 2011 KSCE JOURNAL OF CIVIL ENGINEERING Vol.15 No.1

Corrosion is an electrochemical process which requires electrolyte for the occurrence of corrosion reaction. Therefore it is necessary to calculate the effective corrosion rate with reference to the saturated area of concrete only when it comes to corrosion of steel reinforcement embedded in concrete. Theoretically and numerically the saturated area depends on the capillary zone porosity,gel zone porosity and their respective degree of saturation in the aggregate free volume of concrete which is a heterogeneous material in nature. This makes it important to deeply understand the effect of aggregate on corrosion in concrete. Investigation was carried out to find the effect of coarse aggregate volume on the corrosion rate and potential of reinforcement steel in concrete. The initiative for this research came from the observation that the interfacial transition zone around the steel bar in concrete is surrounded primarily by paste only and hence the coarse aggregate volume should not influence the corrosion rate principally. Also there are chances that some fine aggregate could be present in the vicinity of steel bar surface being finer than coarse aggregate which may affect the corrosion rate. The previous research data in this field was found to be limited and has a difference of opinion. Therefore, these factors have been investigated in this research. Prismatic concrete and mortar specimens were cast and their corrosion potential values were compared with each other to find the effect of the volume of coarse aggregate on corrosion. The experiment results showed that the effect of the volume of coarse aggregate on corrosion potential is not significant since the area around the steel bar especially in the case of deformed steel is mostly surrounded by paste only. The corrosion potential values obtained in the case of mortar and concrete specimens showed same averaged magnitude. This fact was further strengthened by measuring the corrosion mass loss and resulting corrosion rate in the two cases. Furthermore, in the light of experiment results obtained in this research, the numerical FEM model DuCOM developed by our research group at the University of Tokyo, Japan incorporating the effect of aggregate on corrosion rate and potential of corroding steel in concrete undertaken in the past has been successfully enhanced and verified in this research.

Enhanced mass balance Tafel slope model for computer based FEM computation of corrosion rate of steel reinforced concrete coupled with CO_2 transport

Raja Rizwan Hussain 사단법인 한국계산역학회 2011 Computers and Concrete, An International Journal Vol.8 No.2

This research paper aims at computer based modeling of carbonation induced corrosion under extreme conditions and its experimental verification by incorporating enhanced electrochemical and mass balance equations based on thermo-hygro physics with strong coupling of mass transport and equilibrium in micro-pore structure of carbonated concrete for which the previous research data is limited. In this paper the carbonation induced electrochemical corrosion model is developed and coupled with carbon dioxide transport computational model by the use of a concrete durability computer based model DuCOM developed by our research group at concrete laboratory in the University of Tokyo and its reliability is checked in the light of experiment results of carbonation induced corrosion mass loss obtained in this research. The comparison of model analysis and experiment results shows a fair agreement. The carbonation induced corrosion model computation reasonably predicts the quantitative behavior of corrosion rate for normal air dry relative humidity conditions. The computational model developed also shows fair qualitative corrosion rate simulation and analysis for various pH levels and coupled environmental actions of chloride and carbonation. Detailed verification of the model for the quantitative carbonation induced corrosion rate computation under varying relative conditions, different pH levels and combined effects of carbonation and chloride attack remain as scope for future research.

Enhanced Classical Tafel Diagram Model for Corrosion of Steel in Chloride Contaminated Concrete and the Experimental Non-Linear Effect of Temperature

Raja Rizwan Hussain 한국콘크리트학회 2010 International Journal of Concrete Structures and M Vol.4 No.2

The chloride ion attack on the passive iron oxide layer of reinforcement steel embedded in concrete under variable temperature environment is influenced by several parameters and some of them still need to be further investigated in more detail. Different school of thoughts exist between past researchers and the data is limited in the high temperature and high chloride concentration range which is necessary with regards to setting boundary conditions for enhancement of tafel diagram model presented in this research. The objective of this paper is to investigate the detrimental coupled effects of chloride and temperature on corrosion of reinforced concrete structures in the high range by incorporating classical Tafel diagram chloride induced corrosion model and laboratory controlled experimental non-linear effect of temperature on corrosion of rebar embedded in concrete.

Computer based FEM stabilization of oxygen transport model for material and energy simulation in corroding reinforced concrete

Raja Rizwan Hussain 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.12 No.5

This paper unveils a new computer based stabilization methodology for automated modeling analysis and its experimental verification for corrosion in reinforced concrete structures under the effect of varying oxygen concentration. Various corrosion cells with different concrete compositions under four different environmental conditions (air dry, submerged, 95% R.H and alternate wetting-drying) have been investigated under controlled laboratory conditions.The results of these laboratory tests were utilized with an automated computer-aided simulation model. This model based on mass and energy stabilization through the porous media for the corrosion processwas coupled with modified stabilization methodology. By this coupling, it was possible to predict, maintain and transfer the influence of oxygen concentration on the corrosion rate of the reinforcement in concrete under various defined conditions satisfactorily. The variation in oxygen concentration available for corrosion reaction has been taken into account simulating the actual field conditions such as by varying concrete cover depth, relative humidity, water-cement ratio etc. The modeling task has been incorporated by the use of a computer based durability model as a finite element computational approach for stabilizing the effect of oxygen on corrosion of reinforced concrete structures.

Computer based estimation of backbone curves for hysteretic Response of reinforced concrete columns under static cyclic lateral loads

M. Rizwan,M.T.A. Chaudhary,M. Ilyas,Raja Rizwan Hussain,T.R. Stacey 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.14 No.2

Cyclic test of the columns is of practical relevance to the performance of compression members during an earthquake loading. The strength, ductility and energy absorption capabilities of reinforced concrete (RC) columns subjected to cyclic loading have been estimated by many researchers. These characteristics are not normally inherent in plain concrete but can be achieved by effectively confining columns through transverse reinforcement. An extensive experimental program, in which performance of four RC columns detailed according to provisions of ACI-318-08 was studied in contrast with that of four columns confined by a new proposed technique. This paper presents performance of columns reinforced by standard detailing and cast with 25 and 32 MPa concrete. The experimentally achieved load-displacement hysteresis and backbone curves of two columns are presented. The two approaches which work in conjunction with Response 2000 have been suggested to draw analytical back bone curves of RC columns. The experimental and analytical backbone curves are found in good agreement. This investigation gives a detail insight of the response of RC columns subjected to cyclic loads during their service life. The suggested analytical procedures will be available to the engineers involved in design to appraise the capacity of RC columns.

Modeling and simulation of planar SOFC to study the electrochemical properties

Jawad Hussain,Rashid Ali,Majid Niaz Akhtar,Mujtaba Hussain Jaffery,Imran Shakir,Rizwan Raza 한국물리학회 2020 Current Applied Physics Vol.20 No.5

In this paper, modeling and simulations are carried out using COMSOL Multiphysics. A three-dimensional model is developed for a planar intermediate temperature (IT) solid oxide fuel cell (SOFC). A parametric study has been carried out to analyze the performance of SOFC. Simulations reveal some promising features and enhanced performance of SOFC. It is shown that the maximum value of power (4–3.3) kW/m2 still remains higher with significant rise of temperature (600 °C–1000 °C), nearly 0.15 kW/m2 is the very small loss of power per 100 °C rise of temperature. Results have shown that the electrolytic current density is (6700–5500) A/m2 for peak value of power (4–3.3) kW/m2 with increase of temperature (600 °C–1000 °C). For model validation we have plotted a comparison of average current density.

Enhanced Classical Tofel Diagram Model for Corrosion of Steel in Chloride Contaminated Concrete and the Experimental Non Linear Effect of Temperature

Raja Rizwan Hussain 한국콘크리트학회 2010 International Journal of Concrete Structures and M Vol.4 No.2

The chloride ion attack on the passive iron oxide layer of reinforcement steel embedded in concrete under variable temperature environment is influenced by several parameters and some of them still need to be further investigated in more detail. Different school of thoughts exist between past researchers and the data is limited in the high temperature and high chloride concentration range which is necessary with regards to setting boundary conditions for enhancement of tafel diagram model presented in this research. The objective of this paper is to investigate the detrimental coupled effects of chloride and temperature on corrosion of reinforced concrete structures in the high range by incorporating classical Tafel diagram chloride induced corrosion model and laboratory controlled experimental non linear effect of temperature on corrosion of rebar embedded in concrete.

Structural Characterization of Na_0.5Bi_0.5TiO₃ Particles Produced by Different Methods

Hussain, Ali,Maqbool, Adnan,Malik, Rizwan Ahmed,Lee, Jae Hong,Kim, Myong Ho,Song, Tae Kwon,Kim, Won Jeong American Scientific Publishers 2018 Science Of Advanced Materials Vol.10 No.2

<P>This article describes structural characterization of the Na0.5Bi0.5TiO3 (NBT) particles produced using the following techniques: topochemical microcrystal conversion (TMC), molten salt synthesis (MSS) and conventional mixed-oxide (CMO). The NBT particles produced by the TMC method showed high-aspect-ratio plate-like grains. However, the NBT particles prepared by the MSS and CMO methods show equiaxial grains of sizes less than approximately one micron. All NBT particles produced by the three techniques had a similar crystal structure, but different grain orientations. The crystal structure results of these particles were confirmed by transmission electron microscope (TEM) analysis, which showed (100) grain growth for NBT produced by the TMC and along (110) for the same NBT compositions produced by the MSS and CMO methods.</P>