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Intensity measures for the seismic response evaluation of buried steel pipelines under near-field pulse-like ground motions

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Earthquake Engineering and Engineering Vibration 2019年第4期18卷 917-931页

作者： alireza Kiani Mehdi torabi S.Mohammad Mirhosseini Department of Civil Engineering Islamic Azad University Arak Branch Arak 12346 Iran Department of Civil Engineering Islamic Azad University Kangan Branch Kangan 12345 Iran Department of Civil Engineering Islamic Azad University Arak Branch Arak 34125 Iran

Ground-motion Intensity Measures (IMs) are used to quantify the strength of ground motions and evaluate the response of structures. IMs act as a link between seismic demand and seismic hazard analysis and therefore, have a key role in performance-based earthquake engineering. Many studies have been carried out on the determination of suitable IMs in terms of effi ciency, suffi ciency and scaling robustness. The majority of these investigations focused on ordinary structures such as buildings and bridges, and only a few were about buried pipelines. In the current study, the optimal IMs for predicting the seismic demand of continuous buried steel pipelines under near-fi eld pulse-like ground motion records is investigated. Incremental dynamic analysis is performed using twenty ground motion records. Using the results of the regression analysis, the optimality of 23 potential IMs are studied. It is concluded that specifi c energy density (SED) followed by VSI[ω1(PGD+RMSd )] are the optimal IMs based on effi ciency, suffi ciency and scaling robustness for seismic response evaluation of buried pipelines under near-fi eld ground motions.

关键词： continuous buried steel pipeline intensity measure scaling robustness pulse-like ground motion records performance-based earthquake engineering

Nonlocal vibration analysis of circular double-layered graphene sheets resting on an elastic foundation subjected to thermal loading

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Acta Mechanica Sinica 2016年第5期32卷 841-853页

作者： Reza Ansari Jalal torabi Department of Mechanical Engineering University of Guilan

Based on the nonlocal elasticity theory, the vibration behavior of circular double-layered graphene sheets（DLGSs） resting on the Winkler- and Pasternak-type elastic foundations in a thermal environment is *** governing equation is derived on the basis of Eringen＇s nonlocal elasticity and the classical plate theory（CLPT）.The initial thermal loading is assumed to be due to a uniform temperature rise throughout the thickness direction. Using the generalized differential quadrature（GDQ）method and periodic differential operators in radial and circumferential directions, respectively, the governing equation is discretized. DLGSs with clamped and simply-supported boundary conditions are studied and the influence of van der Waals（vd W） interaction forces is taken into *** the numerical results, the effects of various parameters such as elastic medium coefficients, radius-to-thickness ratio,thermal loading and nonlocal parameter are examined on both in-phase and anti-phase natural frequencies. The results show that the thermal load and elastic foundation respectively decreases and increases the fundamental frequencies of DLGSs.

关键词： Circular DLGS Vibration Nonlocal theory Thermal environment Numerical solution

Big Data analytics in oil and gas industry: An emerging trend

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Petroleum 2020年第4期6卷 321-328页

作者： Mehdi Mohammadpoor Farshid torabi Faculty of Engineering and Applied Sciences University of ReginaReginaS4S 0A2SKCanada

This paper reviews the utilization of Big Data analytics,as an emerging trend,in the upstream and downstream oil and gas *** Data or Big Data analytics refers to a new technology which can be employed to handle large datasets which include six main characteristics of volume,variety,velocity,veracity,value,and *** the recent advent of data recording sensors in exploration,drilling,and production operations,oil and gas industry has become a massive data intensive *** seismic and micro-seismic data,improving reservoir characterization and simulation,reducing drilling time and increasing drilling safety,optimization of the performance of production pumps,improved petrochemical asset management,improved shipping and transportation,and improved occupational safety are among some of the applications of Big Data in oil and gas *** the oil and gas industry has become more interested in utilizing Big Data analytics recently,but,there are still challenges mainly due to lack of business support and awareness about the Big Data within the ***,quality of the data and understanding the complexity of the problem are also among the challenging parameters facing the application of Big Data.

关键词： Big Data Hadoop R Oil and gas industry

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Nanoparticle-stabilized CO2 foam flooding for enhanced heavy oil recovery: A micro-optical analysis

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Petroleum 2024年第4期10卷 696-704页

作者： Arifur Rahman Ezeddin Shirif Farshid torabi Petroleum Systems Engineering Faculty of Engineering and Applied Science University of Regina Petroleum and Mining Engineering School of Applied Science & Technology Shahjalal University of Science and Technology

Surfactant flooding is a well-known chemical approach for enhancing oil recovery. Surfactant flooding has the disadvantage that it cannot withstand the harsh reservoir conditions. Improvements in oil recovery and release are made possible by the use of nanoparticles and surfactants and CO2co-injection because they generate stable foam, reduce the interfacial tension（IFT） between water and oil, cause emulsions to spontaneously form, change the wettability of porous media, and change the characteristics of flow. In the current work, the simultaneous injection of SiO2, Al2O3nanoparticles, anionic surfactant SDS, and CO2in various scenarios were evaluated to determine the microscopic and macroscopic efficacy of heavy oil recovery. IFT（interfacial tension） was reduced by 44% when the nanoparticles and SDS（2000 ppm） were added, compared to a reduction of roughly 57% with SDS only. SDS-stabilized CO2foam flooding, however, is unstable due to the adsorption of SDS in the rock surfaces as well as in heavy oil. To assess foam's potential to shift CO2from the high permeability zone（the thief zone） into the low permeability zone, directly visualizing micromodel flooding was successfully executed（upswept oil-rich zone）. Based on typical reservoir permeability fluctuations, the permeability contrast（defined as the ratio of high permeability to low permeability） for the micromodel flooding was selected. However, the results of the experiment demonstrated that by utilizing SDS and nanoparticles, minimal IFT was reached. The addition of nanoparticles to surfactant solutions, however, greatly boosted oil recovery,according to the findings of flooding studies. The ultimate oil recovery was generally improved more by the anionic surfactant（SDS） solution including nanoparticles than by the anionic surfactant（SDS） alone.

关键词： Micromodel CO 2 foam Surfactant Nanoparticles Interfacial tension Heavy oil

Surfactant and nanoparticle synergy:Towards improved foam stability

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Petroleum 2023年第2期9卷 255-264页

作者： Arifur Rahman Farshid torabi Ezeddin Shirif Petroleum Systems Engineering Faculty of Engineering and Applied ScienceUniversity of ReginaReginaSK S4S 0A2Canada Petroleum and Mining Engineering School of Applied Science&TechnologyShahjalal University of Science and TechnologySylhet3114Bangladesh

Surfactant foam stability gets a lot of interest while posing a significant obstacle to many industrial *** of the viable solutions for addressing gas mobility concerns and boosting reservoir fluid sweep efficiency during solvent-based enhanced heavy oil recovery processes is foam *** synergistic effect of nanoparticles and surfactants in a porous reservoir media can help create a more durable and sturdier *** study aims to see how well a combination of the nanoparticles(NPs)and surfactant can generate foam for controlling gas mobility and improving oil *** research looked at the effects of silicon and aluminum oxide nanoparticles on the bulk and dynamic stability of sodium dodecyl surfactant(SDS)-foam in the presence and absence of *** foam height,liquid drainage,half-decay life,nanoparticle deposition,and bubble size distribution of the generated foams with time were used to assess static foam stability in the bulk phase,while dynamic stability was studied in the *** understand the processes of foam stabilization by nanoparticles,the microscopic images of foam and the shape of bubbles were *** nanoparticles were applied in foamability testing in bulk and dynamic phase,the foam generation and stability were improved by 23%and 17%,*** comparison to surfactant alone,adding nanoparticles to surfactant solutions leads to a more significant pressure drop of 17.34 psi for SiO_(2)and 14.86 psi for Al_(2)O_(3)NPs and,as a result,a higher reduction in gas mobility which ultimately assists in enhancing oil recovery.

关键词： Foam stability Nanoparticles Surfactant Foam decay Pressure drop Enhanced oil recovery Etc

Practical autoencoder based anomaly detection by using vector reconstruction error

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Cybersecurity 2023年第2期6卷 1-13页

作者： Hasan torabi Seyedeh Leili Mirtaheri Sergio Greco Department of Electrical and Computer Engineering Faculty of EngineeringKharazmi UniversityTehranIran Department of Informatics ModelingElectronics and System EngineeringUniversity of CalabriaArcavacataItaly.

Nowadays,cloud computing provides easy access to a set of variable and configurable computing resources based on user demand through the *** computing services are available through common internet protocols and network standards.n addition to the unique benefits of cloud computing,insecure communication and attacks on cloud networks cannot be *** are several techniques for dealing with network *** this end,network anomaly detection systems are widely used as an effective countermeasure against network *** anomaly-based approach generally learns normal traffic patterns in various ways and identifies patterns of *** anomaly detection systems have gained much attention in intelligently monitoring network traffic using machine learning *** paper presents an efficient model based on autoencoders for anomaly detection in cloud computing *** autoencoder learns a basic representation of the normal data and its reconstruction with minimum ***,the reconstruction error is used as an anomaly or classification *** addition,to detecting anomaly data from normal data,the classification of anomaly types has also been *** have proposed a new approach by examining an autoencoder's anomaly detection method based on data reconstruction *** the existing autoencoder-based anomaly detection techniques that consider the reconstruction error of all input features as a single value,we assume that the reconstruction error is a *** enables our model to use the reconstruction error of every input feature as an anomaly or classification *** further propose a multi-class classification structure to classify the *** use the CIDDS-001 dataset as a commonly accepted dataset in the *** evaluations show that the performance of the proposed method has improved considerably compared to the existing ones in terms of accuracy,recall,false-positive rate,and F1-score

关键词： Cloud Practical Anomaly detection Autoencoder Reconstruction error Machine learning

Assessment of novel nature-inspired fuzzy models for predicting long contraction scouring and related uncertainties

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Frontiers of Structural and Civil Engineering 2021年第3期15卷 665-681页

作者： Ahmad SHARAFATI Masoud HAGHBIN Mohammadamin torabi Zaher Mundher YASEEN Department of Civil Engineering Science and Research BranchIslamic Azad UniversityTehranIran Department of Structural Mechanics&Hydraulics Engineering University of GranadaGranada18001Spain EIT.Schnabel Engineering Chadds FordPA19317USA New Era and Development in Civil Engineering Research Group Scientific Research CenterAl-Ayen UniversityThi-Qar64001Iraq

The scouring phenomenon is one of the major problems experienced in hydraulic *** this study,an adaptive neuro-fuzzy inference system is hybridized with several evolutionary approaches,including the ant colony optimization,genetic algorithm,teaching-learning-based optimization,biogeographical-based optimization,and invasive weed optimization for estimating the long contraction scour *** proposed hybrid models are built using non-dimensional information collected from previous *** proposed hybrid intelligent models are evaluated using several statistical performance metrics and graphical ***,the uncertainty of models,variables,and data are *** on the achieved modeling results,adaptive neuro-fuzzy inference system-biogeographic based optimization(ANFIS-BBO)provides superior prediction accuracy compared to others,with a maximum correlation coefficient(R_(test)=0.923)and minimum root mean square error value(RMSE_(test)=0.0193).Thus,the proposed ANFIS-BBO is a capable cost-effective method for predicting long contraction scouring,thus,contributing to the base knowledge of hydraulic structure sustainability.

关键词： long contraction scour prediction uncertainty ANFIS model meta-heuristic algorithm

Effects of weathering depth and thickness on rock failure:Experimental approach and particle flow code simulation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第11期16卷 4638-4653页

作者： Vahab Sarfarazi Mehdi torabi-Kaveh Arsham Moayedi Far Mining Engineering Department Hamedan University of TechnologyHamedan57965155Iran Department of Geology Yazd UniversityYazd***Iran Montanuniversitat Leoben Franz Josef Straße 18Leoben8700Austria

This study investigated the effects of weathering depth and thickness on the failure mechanisms of rock samples through experimental and numerical *** first configuration involved conducting artificial weathering on limestone using the freezing and thawing(F-T)for 40 *** mechanical parameters of the samples were measured at the end of the 40th *** the second configuration,a series of specimens underwent salt crystallization(S-C)tests for 20 *** results were validated using discrete element method(DEM).Next,the weathered limestone model with dimensions of 108 mm54 mm were *** weathering layers were tested at four different thicknesses(i.e.2.5 mm,5 mm,7.5 mm,and 10 mm)and three different positions(at the surface,5 mm under the rock surface,and 10 mm under the rock surface).According to the results,weathering depth and thickness have a considerable effect on the failure *** results also showed a correlation between the values of compressive strength and failure mechanisms associated with the weathering *** numerical results revealed that the tension crack was the dominant ***,with increasing weathering thickness,Young's modulus,crack initiation stress,and final strength decreased in constant weathering *** results also demonstrated that the failure progress of the numerical models was similar to that observed in the laboratory.

关键词： Limestone Weathering depth Weathering thickness Failure pattern Particle flow code in two dimensions(PFC2D)

Molecular design and applications of a nanostructure green Tripodal surface active ionic liquid in enhanced oil recovery: Interfacial tension reduction, wettability alteration, and emulsification

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Petroleum Science 2023年第6期20卷 3530-3539页

作者： Mona Kharazi Javad Saien Morteza torabi Mohammad Ali Zolfigol Faculty of Chemistry and Petroleum Science Bu–Ali Sina UniversityHamedan***Iran

Surface active ionic liquids (SAILs) are considered as prominent materials in enhanced oil recovery thanks to their high interfacial activity. This study reports the preparation and applications of a nanostructure Tripodal imidazolium SAIL as an environmentally-friendly substitute to the conventional surfactants. The product has a star-like molecular structure centered by a triazine spacer, namely [(C_(4)im)_(3)TA][Cl_(3)], prepared by a one-step synthesis method and characterized with FT-IR, NMR, XRD, and SEM analysis methods. The interfacial tension of the system was decreased to about 78% at critical micelle concentration of less than 0.08 mol·dm^(−3). Increasing temperature, from 298.2 to 323.2 K, improved this capability. The solid surface wettability was changed from oil-wet to water-wet and 80% and 77% stable emulsions of crude oil–aqueous solutions were created after one day and one week, respectively. Compared to the Gemini kind homologous SAILs, the superior effects of the Tripodal SAIL were revealed and attributed to the strong hydrophobic branches in the molecule. The Frumkin adsorption isotherm precisely reproduced the generated IFT data, and accordingly, the adsorption and thermodynamic parameters were determined.

关键词： Tripodal ionic liquids Green materials Enhanced oil recovery Interfacial tension Wettability Emulsification