A data mining approach to compressive strength of CFRP-confined concrete cylinders

Mousavi, S.M.,Alavi, A.H.,Gandomi, A.H.,Esmaeili, M. Arab,Gandomi, M. Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.6

In this paper, compressive strength of carbon fiber reinforced polymer (CFRP) confined concrete cylinders is formulated using a hybrid method coupling genetic programming (GP) and simulated annealing (SA), called GP/SA, and a robust variant of GP, namely multi expression programming (MEP). Straightforward GP/SA and MEP-based prediction equations are derived for the compressive strength of CFRP-wrapped concrete cylinders. The models are constructed using two sets of predictor variables. The first set comprises diameter of concrete cylinder, unconfined concrete strength, tensile strength of CFRP laminate, and total thickness of CFRP layer. The most widely used parameters of unconfined concrete strength and ultimate confinement pressure are included in the second set. The models are developed based on the experimental results obtained from the literature. To verify the applicability of the proposed models, they are employed to estimate the compressive strength of parts of test results that were not included in the modeling process. A sensitivity analysis is carried out to determine the contributions of the parameters affecting the compressive strength. For more verification, a parametric study is carried out and the trends of the results are confirmed via some previous studies. The GP/SA and MEP models are able to predict the ultimate compressive strength with an acceptable level of accuracy. The proposed models perform superior than several CFRP confinement models found in the literature. The derived models are particularly valuable for pre-design purposes.

A review on ions induced contamination of polymer electrolyte membrane fuel cells, poisoning mechanisms and mitigation approaches

S. Mohsen Mousavi Ehteshami,Amirhooshang Taheri,S.H. Chan 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.34 No.-

Impurities diminish the performance of PEM fuel cells significantly. Impurities are either introduced intothe cell via feedstock or are generated within the cell during operation. The presence of ions like Clremarkably affects the cell performance. For example, 1 ppm chloride ion causes a loss of 150 mV at0.75 A cm 2 [1]. This paper reviews the effects of ions on the cell performance, and discusses thepoisoning mechanisms, mitigation approaches, and future research perspectives. Understanding theeffects of ions on the cell performance and poisoning mechanisms enable taking appropriate pathstowards more efficient and cost-effective application of PEM fuel cells.

Modeling of compressive strength of HPC mixes using a combined algorithm of genetic programming and orthogonal least squares

Mousavi, S.M.,Gandomi, A.H.,Alavi, A.H.,Vesalimahmood, M. Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.2

In this study, a hybrid search algorithm combining genetic programming with orthogonal least squares (GP/OLS) is utilized to generate prediction models for compressive strength of high performance concrete (HPC) mixes. The GP/OLS models are developed based on a comprehensive database containing 1133 experimental test results obtained from previously published papers. A multiple least squares regression (LSR) analysis is performed to benchmark the GP/OLS models. A subsequent parametric study is carried out to verify the validity of the models. The results indicate that the proposed models are effectively capable of evaluating the compressive strength of HPC mixes. The derived formulas are very simple, straightforward and provide an analysis tool accessible to practicing engineers.

Study on the Mite Founa of Potato Fields in Iran West Azarbayjan Province

S. H. Mousavi,H. Ostvan,K. Kamali 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05

Characterization of produced xylanase by Bacillus subtilis D3d newly isolated from apricot phyllosphere and its potential in pre-digestion of BSG

H. Moteshafi,M. Hashemi,S.M. Mousavi,M. Mousivand 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.37 No.-

Bacillus subtilis D3d newly isolated from apricot phyllosphere has the potential of producing high levelsof xylanase. The present study used response surface methodology (RSM) to optimize catalytic activity. Factors including temperature, pH and beechwood xylan concentration were optimized using centralcomposite design (CCD). Under optimized condition maximum xylanase activity found 260 U/ml. Theenzyme showed stability over a range of pH (5.0–9.0) and exhibited more than 80% activity after 72 h at40 8C. Such RSM models as well as stability data can be used at different operational conditions to predictthe residual catalytic activity. Regard to pre-digested brewer’s spent grain (BSG) has potential as avaluable poultry B. subtilis D3d crude xylanase. Maximum reducing sugar yield were found to be68.43 mgreducing sugars/gBSG at optimum condition. The results revealed that B.subtilis D3d is a promisingxylanase-producing bacterium with great potential for use in the food and feed industries.

A data mining approach to compressive strength of CFRP-confined concrete cylinders

S.M. Mousavi,A.H. Alavi,A.H. Gandomi,M. Arab Esmaeili,M. Gandomi 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.6

In this paper, compressive strength of carbon fiber reinforced polymer (CFRP) confined concrete cylinders is formulated using a hybrid method coupling genetic programming (GP) and simulated annealing (SA), called GP/SA, and a robust variant of GP, namely multi expression programming (MEP). Straightforward GP/SA and MEP-based prediction equations are derived for the compressive strength of CFRP-wrapped concrete cylinders. The models are constructed using two sets of predictor variables. The first set comprises diameter of concrete cylinder, unconfined concrete strength, tensile strength of CFRP laminate, and total thickness of CFRP layer. The most widely used parameters of unconfined concrete strength and ultimate confinement pressure are included in the second set. The models are developed based on the experimental results obtained from the literature. To verify the applicability of the proposed models, they are employed to estimate the compressive strength of parts of test results that were not included in the modeling process. A sensitivity analysis is carried out to determine the contributions of the parameters affecting the compressive strength. For more verification, a parametric study is carried out and the trends of the results are confirmed via some previous studies. The GP/SA and MEP models are able to predict the ultimate compressive strength with an acceptable level of accuracy. The proposed models perform superior than several CFRP confinement models found in the literature. The derived models are particularly valuable for pre-design purposes.

Modeling of compressive strength of HPC mixes using a combined algorithm of genetic programming and orthogonal least squares

S.M. Mousavi,A.H. Gandomi,A.H. Alavi,M. Vesalimahmood 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.2

In this study, a hybrid search algorithm combining genetic programming with orthogonal least squares (GP/OLS) is utilized to generate prediction models for compressive strength of high performance concrete (HPC) mixes. The GP/OLS models are developed based on a comprehensive database containing 1133 experimental test results obtained from previously published papers. A multiple least squares regression (LSR) analysis is performed to benchmark the GP/OLS models. A subsequent parametric study is carried out to verify the validity of the models. The results indicate that the proposed models are effectively capable of evaluating the compressive strength of HPC mixes. The derived formulas are very simple, straightforward and provide an analysis tool accessible to practicing engineers.

Investigation of nonlinear optical responses and observing diffraction rings in acid dye (Patent Green)

M.H. Majles Ara,S. Salmani,S.H. Mousavi,E. Koushki 한국물리학회 2010 Current Applied Physics Vol.10 No.4

The nonlinear optical responses and diffraction pattern in far-field of a dye type acid (Patent Green) are investigated with irradiation of 75mW CW He-Ne laser. The second-order nonlinear refractive index and absorption coefficient of acid dye in different concentrations are measured using z-scan technique. But diffraction pattern in far-field for some concentrations of the dye culminates in observing large phase shifts which cannot be accounted for. At low laser powers, the z-scan equations are valid because Δ□0 < π. However; the phase shifts becomes more than π with when experiments are conducted with high laser power in dye solutions of high concentration. But the phase shift reach to more than in the both high powers and high concentrations therefore it would be possible to observe the far-field diffraction pattern. Further, it is demonstrated that both nonlinear refraction and absorption increase with increasing concentration and power.

A comprehensive study of microstructure development and its corresponding tensile properties in nano/ultrafine-grained metastable austenitic steel during accumulative roll bonding (ARB)

Jafarian, H.R.,Anijdan, S.H. Mousavi,Eivani, A.R.,Park, N. Elsevier 2017 Materials science & engineering. properties, micro Vol.703 No.-

<P><B>Abstract</B></P> <P>The evolution of microstructure together with mechanical properties change of Fe-28.5Ni steel, used in design of marine and nuclear related products, processed by different deformation amount during ARB process was elaborated by Electron Backscattered Diffraction (EBSD) method. EBSD results showed that the initial structure of the material contained retained austenite as the main phase besides martensite phase. Martensite phase was diminished after successive ARB cycles due to reduction of martensite start (M<SUB>s</SUB>) temperature. EBSD microstructural results exhibited that a stabilized nano structure was attained by 6-cycle or 8-cycle of the ARB process with the latter having slightly higher grain size due to the grain growth effect of dynamic restoration mechanism resulting from extreme deformation. Tensile test data on different cycles of ARB processed specimens showed that yield and ultimate tensile strengths were substantially increased after the first cycle of the ARB coinciding with the substantial amount of dislocations in the form of low angle grain boundaries (LAGB). Strengths increased in the successive cycles, though in a much slower pace. Ultra-fine grains were formed instead after high cycles of ARB process. Although such increase in strength generally came at the expense of ductility, the material after 8-cycle had still substantial ductility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fe-28.5Ni contained two phases of retained austenite and martensite. </LI> <LI> Martensite phase is reduced and austenite stabilized during ARB process. </LI> <LI> A nano grain size structure is developed after severe plastic deformation. </LI> <LI> Extreme deformation slightly increases the grain size by dynamic restoration process. </LI> <LI> Substantial amount of ductility was achieved in SPD due to austenite stabilization. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Optical characterization of Erioglaucine using z-scan technique, beam radius variations and diffraction pattern in far-field

M.H. Majles Ara,S. Salmani,M. Esmaeilzadeh,S.H. Mousavi,E. Koushki,Kh. Shakouri 한국물리학회 2009 Current Applied Physics Vol.9 No.5

In this paper, we observed optical responses of Erioglaucine (acid blue 9) with several techniques in different concentrations. Experimental setups are similar to standard z-scan; close and open setups were employed to determine the nonlinear refraction and nonlinear absorption coefficients, respectively. It is interesting during the experiments, every concentration has various behaviors. As the phase shift in some concentrations is greater than π, then z-can equations are not valid; therefore, we indicated the nonlinear responses by beam radius variations for π < |△Φ0| < 2π; and then compared some numerical calculations and diffraction patterns observed in far-field for |△Φ0| ≽ 2π.