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  • دکتری (1371)

    مهندسی عمران - ژئوتکنیک

    نیوکاسل، انگلستان

  • کارشناسی‌ارشد (1368)

    مهندسی عمران - ژئوتکنیک

    نیوکاسل، انگلستان

  • کارشناسی (1365)

    مهندسی معدن

    دانشگاه صنعتی امیرکبیر،

  • اندازه گیری تنش های برجا در سنگ
  • ژئو مکانیک نفت
  • رفتار وابسته به زمان سازه‌های سنگی
  • خزش و اکوستیک

    زمینه های پژوهشی:

    کارشناس مسئول: فرهاد احمدي شيخاني

    تلفن:

    مکان: ضلع جنوبي ب6 ط1-

اینجانب در سال 1372 فارغ التحصیل شده ام

ارتباط

رزومه

Plasma-treated room temperature synthesized CuCrO2/Au/CuCrO2 on Polyethylene terephthalate: Towards a high-performance flexible p-type transparent coductor

Morteza Ahmadi, Saeed Javadi Anaghizi, Morteza Asemi, Majid Ghanaatshoar
Journal PapersThin Solid Films , 2021 February 16, {Pages 138582 }

Abstract

TCO/metal/TCO multilayer structures have been long used to improve the properties of transparent conducting oxides (TCOs). Herein, we investigated the influence of direct current-sputtered gold (Au) sandwiched between two CuCrO2 (CCO) layers deposited by radio frequency-sputtering at room temperature on quartz substrates. We show that this structure has the capability to increase the electrical conductivity significantly while maintaining suitable transparency. The resistivity of our optimized structure was ∼28 Ω/sq, and its average transparency in the visible region was around 42%. We also showed that this structure has the capability to be deposited on polyethylene terephthalate (PET) flexible substrates with comparable properties, and

Computational microstructural model of ordinary state-based Peridynamic theory for damage mechanisms, void nucleation, and propagation in DP600 steel

Morteza Ahmadi, Mojtaba Sadighi, Hossein Hosseini Toudeshky
Journal PapersEngineering Fracture Mechanics , 2021 March 6, {Pages 107660 }

Abstract

In this study, the evolution of microscopic damage mechanisms in DP600 was investigated by developing an ordinary state-based two-dimensional Peridynamic model. The real microstructure was extracted from scanning electron microscope (SEM) images and employed to predict the deformation and damage behavior of dual-phase (DP) steels under tension static loading. Isotropic hardening plasticity and nonlinear failure criterion were considered for both ferrite and martensite phases. The Peridynamic (PD) modeling procedure is improved to reduce simulation time and increase applied displacement steps. For improving the prediction of damage initiation, a new method was proposed for the properties of the martensite/ferrite interface. At four applied s

Simulation of hydraulic fracturing and Darcy fluid flow in a porous medium using a coupled Discrete Element Method with fluid flow

Ali Asghar Safari Varzaneh, Morteza Ahmadi, Kamran Goshtasbi
Journal PapersJournal of Petroleum Science and Engineering , 2021 March 24, {Pages 108706 }

Abstract

Studying fluid penetration of the rock matrix during fracture propagation is one of the most difficult technical challenges of hydraulic fracture engineering. To deal with this issue, a coupled hydraulic-mechanical model was performed to simulate fracture propagation during hydraulic fracturing. For this purpose, a new discrete elements approach with a force-displacement law was used for simulating the fracturing process in a flow-coupled Discrete Element Method (DEM). A series of cases was simulated to evaluate the effect of different rates of injection and permeability. Good agreement was obtained between the numerical results of this study and the reported experimental results. The results of hydraulic fracture modeling indicated that a

Stability analysis of complex behavior of salt cavern subjected to cyclic loading by laboratory measurement and numerical modeling using LOCAS (case study: Nasrabad gas storage?…

Rahim Habibi, Hassan Moomivand, Mortez Ahmadi, Amin Asgari
Journal PapersEnvironmental Earth Sciences , Volume 80 , Issue 8, 2021 April , {Pages 21-Jan }

Abstract

Stability analysis of salt caverns is a very complicated subject due to the coupled time-dependent thermo-mechanical behavior of salt during leaching and operational phase of the gas storage subjected to the cyclic loading. Because of purely plastic behavior of salt and the relevant convergence during injection and withdrawal, investigation of the salt cavern stability becomes more challenging. The objective of this study is stability analysis of Nasrabad salt cavern by numerical method using a comprehensive software entitled LOCAS having capability to model the complex time-dependent thermo-mechanical behavior of salt under cyclic loading of natural gas pressure. Measurement of geomechanical properties of salt is also the important require

Stability analysis of complex behavior of salt cavern subjected to cyclic loading by laboratory measurement and numerical modeling using LOCAS (case study: Nasrabad gas storage …

R Habibi, H Moomivand, M Ahmadi, A Asgari
Journal Papers , , {Pages }

Abstract

Seismic Analysis of Soil-Nailed Walls Using the Modified Pseudo-Dynamic Method

M Ahmadi, M Jiryaei Sharahi, B Badarloo
Journal Papers , , {Pages }

Abstract

Analytical Solutions for Entanglement A Superposition of Spin Coherent States with Non-Phase Coherence Parameters

M Ashrafpour, M Ahmadi, M Jafarpour
Journal Papers , , {Pages }

Abstract

Scaling geological fracture network from a micro to a macro scale

Rouhollah Basirat, Kamran Goshtasbi, Morteza Ahmadi
Journal PapersFrattura ed Integrit? Strutturale , Volume 14 , Issue 51, 2020 January , {Pages 71-80 }

Abstract

Characterizing fracture systems at various scales, modeling fracture distributions, and clarifying scale relations that correlate total fracture systems are of paramount importance in geology, mining, civil engineering, and petroleum engineering. In this paper, the conditions of fracture network geometry are investigated in a field scale (about 100 m) and a core sample scale (several centimeters). To achieve this purpose, field surveys and coring of rock outcrops were performed in the Asmari Formation of Iran. Fractures were manually sampled from rock outcrops on the field scale while micro-fractures were surveyed using CT-scan images of core samples on a small scale. To compare the fracture network geometry, two perspectives of fractal dim

Study of damage zone around a circular opening using acoustic emission technique

Morteza Ahmadi, Ali Dadi-givshad, Hamid Reza Nejati
Journal PapersJournal of Mining and Environment , 2020 February 20, {Pages }

Abstract

One of the methods used to investigate the damaged zone in rock structure is the acoustic emission method. This method is based on receiving the elastic waves that are produced by deformation and cracking of the rock mass around the underground excavation. In this research, a study is conducted on the rock samples by a numerical method to investigate the damaged zone caused by the excavation of circular space on it. For this purpose, 33 cube samples of three different material types including sandstone, concrete, and cement-plaster mortar are prepared. A circular hole is drilled in the center of each sample. The hole diameter is 20 or 25 mm. The samples are loaded uniaxially or biaxially with different stress rates. It is tried to study the

Generalized quasi-Baer -rings and Banach -algebras

Morteza Ahmadi, Nasser Golestani, Ahmad Moussavi
Journal PapersCommunications in Algebra , Volume 48 , Issue 5, 2020 May 3, {Pages 2207-2247 }

Abstract

We say that a -ring R is a generalized quasi-Baer -ring if for any ideal I of the right annihilator of is generated, as a right ideal, by a projection, for some positive integer n depending on I. A unital -ring R is left primary if and only if R is a generalized quasi-Baer -ring with no nontrivial central projections. We study basic properties of such rings and we prove their permanence properties such as the Morita invariance. We show that this notion is well-behaved with respect to polynomial extensions and certain triangular matrix extensions and group rings. A sheaf representation for such -rings is also proved. We obtain algebraic examples which are generalized quasi-Baer -rings but are not quasi-Baer -rings. We show that for pre-C*-

ISTRAŽIVANJE ČVRSTOĆE I MEHANIZMA NASTANKA FRAKTURA U ANIZOTROPNIM STIJENAMA METODOM ODAŠILJANJA ZVUKA

Hadi Zadsar, Masoud Cheraghi Seifabad, Morteza Ahmadi
Journal PapersRudarsko-geološko-naftni zbornik , Volume 35 , Issue 2, 2020 April 24, {Pages 15-21 }

Abstract

Anizotropija u stijenama jedan je od najvažnijih parametara u istraživanju fraktura. Ispitivanje zvučnim valovima metoda je koja se upotrebljava za proučavanje nastanka i rasta mikrofraktura. Tako se mogu prepoznati vrste stresa i naprezanja. U ovome radu istražen je utjecaj kuta anizotropije na čvrstoću i postanak fraktura uporabom metode Cracked Chevron Notched Brazilian Disc (CCNBD). Ispitani su uzorci slejta kao tipske anizotropne stijene, uzeti u zoni SanandajSirjan u Iranu. Veličina uzoraka bila je promjera 54 i 74 mm te debljine 24 i 37 mm. Za ispitivanje su odabrani anizotropni kutovi 0, 15, 30, 45, 60, 75 i 90. Testovi su načinjeni s preporukama Međunarodnoga društva za mehaniku stijena (International Society for Rock Me

Study of Damaged Zone around Circular Opening Using Acoustic Emission Technique

A Dadi-givshad, M Ahmadi, Hamid Reza Nejati
Journal PapersJournal of Mining and Environment , Volume 11 , Issue 2, 2020 April 1, {Pages 433-451 }

Abstract

One of the methods used to investigate the damaged zone in rock structure is the acoustic emission method. This method is based on receiving the elastic waves that are produced by deformation and cracking of the rock mass around the underground excavation. In this research, a study is conducted on the rock samples by a numerical method to investigate the damaged zone caused by the excavation of circular space on it. For this purpose, 33 cube samples of three different material types including sandstone, concrete, and cement-plaster mortar are prepared. A circular hole is drilled in the center of each sample. The hole diameter is 20 or 25 mm. The samples are loaded uniaxially or biaxially with different stress rates. It is tried to study the

An investigation into fracture toughness and mechanisms in anisotropic rocks using the Acoustic Emission method

Masoud Cheraghi Seifabad, Hadi Zadsar, Morteza Ahmadi
Journal PapersRudarsko-geološko-naftni zbornik , Volume 35 , Issue 2, 2020 February 6, {Pages }

Abstract

Anisotropy in rock is among the important parameters that should be considered in studying fracture toughness and fracture mechanisms. Acoustic emission is one of the methods applied to investigate fracture mechanics and how micro-cracks grow in rock samples. This method can help to identify different parts of stress versus strain curves. Using this method, the current research aims to study the effect of anisotropy angles on fracture toughness and fracture mecha-nisms of rock samples. To study the designated parameters, the Cracked Chevron Notched Brazilian Disc (CCNBD) method was selected. Blocks of slate, as an anisotropic rock, were prepared from the Sanandaj-Sirjan zone in Iran. The sample sizes were 54 mm and 74 mm in diameter and 24

Peridynamic micromechanical modeling of plastic deformation and progressive damage prediction in dual-phase materials

Morteza Ahmadi, Hossein Hosseini-Toudeshky, Mojtaba Sadighi
Journal PapersEngineering Fracture Mechanics , 2020 June 23, {Pages 107179 }

Abstract

In this study, a state-based Peridynamic (PD) microstructure model is developed to simulate the damage initiation and propagation and plastic deformation in multi-phase materials. The dual-phase (DP) steel is utilized as a material example. A two-dimensional PD model is developed to predict the response of three representative volume elements (RVEs) under tension static loading. RVEs are extracted from Scanning electron microscopy (SEM) images by image processing. Von Mises yield criterion with hardening is used to model plastic deformation. Failure criteria are achieved by relating PD total work needed for eliminating the interactions to the critical energy release rate. A new approach is also proposed for boundary conditions and assigning

Rings whose singular ideals are nil

M Ahmadi, A Moussavi
Journal PapersCommunications in Algebra , Volume 48 , Issue 11, 2020 November 1, {Pages 4796-4808 }

Abstract

It is well known that when a ring R satisfies ACC on right annihilators of elements, then the right singular ideal of R is nil, in this case, we say R is right nil-singular. Many classes of rings whose singular ideals are nil, but do not satisfy the ACC on right annihilators, are presented and the behavior of them is investigated with respect to various constructions, in particular skew polynomial rings and triangular matrix rings. The class of right nil-singular rings contains π-regular rings and is closed under direct sums. Examples are provided to explain and delimit our results.

Efficiency enhancement in dye-sensitized solar cells through the decoration of electro-spun TiO 2 nanofibers with Ag nanoparticles

Atiye Moradi, Masoud Abrari, Morteza Ahmadi
Journal PapersJournal of Materials Science: Materials in Electronics , 2020 August 19, {Pages 10-Jan }

Abstract

Dye-sensitized solar cells (DSSCs) are low cost and eco-friendly photovoltaic devices which require new ideas for further development. In this paper, we use electro-spun TiO 2 nanofibers to prepare the DSSCs photoanode. In order to isolate the FTO and electrolyte species, we deposit a spin-coated TiO 2 blocking layer at their interface. The performance of this cell is further improved by introducing surface plasmon resonances (SPRs) at the surface of the nanofibers. It is shown that SPRs increase the generated current in the cells by providing a higher light absorption and lower recombination. Our best cell showed an efficiency of 6.19%, which is a 28% improvement in comparison to the bare DSSC with 4.84% efficiency. The results of this pap

Effects of substrate temperature and reactive gas flow rate on the crystalline ceramic phases formation and tribological properties of W–Ti–Co–C–N thin films produced by co?…

SA Ataie, M Soltanieh, R Naghizadeh, M Ahmadi, M Ghanaatshoar
Journal PapersCeramics International , 2020 August 13, {Pages }

Abstract

The present study investigates the deposition condition of W–Ti–Co–C–N thin films made by magnetron co-sputtering. The central composite design of experiments was applied for analyzing the effect of substrate temperature (X1) and nitrogen gas flow rate (X2) on the mechanical properties. Nanoindentation, sliding wear test (ball-on-disk method), scanning electron microscopy, atomic force microscopy, and X-ray diffraction techniques were employed to evaluate the tribological properties and microstructure of the thin films. The optimum values of variables were found to be in the range of 500??C?

Analytical solutions for entanglement a superposition of spin coherent states with non-phase coherence parameters

Mehrzad Ashrafpour, Morteza Ahmadi, Mojtaba Jafarpour
Journal PapersJournal of Sciences, Islamic Republic of Iran , 2020 July 22, {Pages }

Abstract

In this work, the entanglement superposition of qubit bipartite coherent states with non-phase coherent parameters was investigated. To quantify the entanglement generalized concurrence measure was used. Through using generalized concurrence measure definition and analytical calculation, the solution for the introduced states in this work were obtained in terms of effective parameters. The calculated analytical solution for effective superposition and coherence parameters showed these states may attain maximum entanglement or no entanglement at all, depending on the choice of the parameters involved.

McCoy property of Hurwitz series rings

Vahid Nourozi, Farhad Rahmati, Morteza Ahmadi
Journal PapersAsian-European Journal of Mathematics , 2020 August 21, {Pages 2150105 }

Abstract

Based on a theorem of McCoy on commutative rings, Nielsen called a ring right McCoy if for any nonzero polynomials over , implies for some . In this note, we introduce and investigate McCoy and -properties of Hurwitz series ring and its Hurwitz polynomial subring . We show that when is a reversible or duo ring and then the Hurwitz polynomial ring is McCoy.

The influence of radio-frequency sputtered blocking layer on boosting the performance of BaSnO3-based dye-sensitized solar cell

Hamed Azari Najafabadi, Morteza Ahmadi, Majid Ghanaatshoar
Journal PapersThin Solid Films , 2020 September 19, {Pages 138346 }

Abstract

The efficiency of dye-sensitized solar cells (DSSCs) is limited by the recombination of electrons in fluorine-doped tin oxide (FTO) with the electrolyte species at the FTO/mesoporous semiconductor interface. This predicament can be addressed by employing a dense blocking layer (BL). Herein, we investigate the effects of BaSnO3 (BSO) thin film deposited by the radio-frequency sputtering method as a BL in BSO-based DSSCs. A range of thicknesses of up to 100 nm are examined, and it is shown that a thickness of ∼50 nm is the optimum value for BL in BSO-based DSSCs. This BL can generate an efficiency enhancement of about 50% from 2.6% for bare BSO-based DSSC to 3.9% for the DSSC with a ∼50 nm BL. This improvement is achieved by surpassing th

دروس نیمسال جاری

  • دكتري
    مكانيك شكست پيشرفته (3 واحد)
    دانشکده فنی و مهندسی، گروه مكانيك سنگ
  • كارشناسي ارشد
    مكانيك محيط هاي پيوسته در سنگ (3 واحد)

دروس نیمسال قبل

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