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hydraulics
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Feasibility of using laser bit beside of common bits to drilling slim holes
, Article Society of Petroleum Engineers - International Petroleum Technology Conference 2013, IPTC 2013: Challenging Technology and Economic Limits to Meet the Global Energy Demand ; Volume 1 , 2013 , Pages 422-433 ; 9781627481762 (ISBN) ; Jalalyfar, H ; Koohian, A ; Habibpour, M ; Sharif University of Technology
2013
Abstract
The capability level of rotary as well as first generation drilling operation could not be matched for deeply drilling programs. To reach that deep, the increasing in drill string length could also cause an additional constraint on hydraulic performance. The operation of slim hole drilling has significant potential to reduce well costs. This cost might be savings are especially important with increased demand for reduced capital finance under current economic conditions in the Iranian oil and gas industry. This savings achievement could be caused by use of smaller drilling rigs, work over rigs, reduced casing size, reducing requirement for drilling consumables and other costs associated with...
Evaluation of methods for estimating aquifer hydraulic parameters
, Article Applied Soft Computing Journal ; Volume 28 , March , 2015 , Pages 541-549 ; 15684946 (ISSN) ; Mortazavi Naeini, M ; Ataie Ashtiani, B ; Jeng, D. S ; Khanbilvardi, R ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
An accurate estimation of aquifer hydraulic parameters is required for groundwater modeling and proper management of vital groundwater resources. In situ measurements of aquifer hydraulic parameters are expensive and difficult. Traditionally, these parameters have been estimated by graphical methods that are approximate and time-consuming. As a result, nonlinear programming (NLP) techniques have been used extensively to estimate them. Despite the outperformance of NLP approaches over graphical methods, they tend to converge to local minima and typically suffer from a convergence problem. In this study, Genetic Algorithm (GA) and Ant Colony Optimization (ACO) methods are used to identify...
Modeling of cohesive crack growth in partially saturated porous media; A study on the permeability of cohesive fracture
, Article International Journal of Fracture ; Volume 167, Issue 1 , Jan , 2011 , Pages 15-31 ; 03769429 (ISSN) ; Khoei, A. R ; Mofid, M ; Sharif University of Technology
Abstract
Modeling the water flow in cohesive fracture is a fundamental issue in the crack growth simulation of cracked concrete gravity dams and hydraulic fracture problems. In this paper, a mathematical model is presented for the analysis of fracture propagation in the semi-saturated porous media. The solid behavior incorporates a discrete cohesive fracture model, coupled with the flow in porous media through the fracture network. The double-nodded zero-thickness cohesive interface element is employed for the mixed mode fracture behavior in tension and contact behavior in compression. The modified crack permeability is applied in fracture propagation based on the data obtained from experimental...
Model-based fuzzy control of a gas turbine coupled with a dynamometer
, Article Journal of Propulsion and Power ; Volume 34, Issue 5 , 2018 , Pages 1178-1188 ; 07484658 (ISSN) ; Abdollahi Gol, H ; Sharif University of Technology
American Institute of Aeronautics and Astronautics Inc
2018
Abstract
This paper discusses a novel and detailed approach for dynamic modeling and control design of a coupled hydraulic dynamometer/turbine-engine system. This study presents a comprehensive model to reveal the coupling effects and an adaptive multiobjective controller to ensure a safe and reliable operation. A fuzzy-based strategy is employed to dynamically adjust the controller gains to keep the state variables and power loading within the desirable operational limits. This approach uses the dynamometer inlet, outlet, and trim valves as well as the turbine fuel flow rate and bleed valve in order to control the system performance during the engine testing process. The proposed fuzzy control...
Spatially distributed influence of agro-environmental factors governing nitrate fate and transport in an irrigated stream-aquifer system
, Article Hydrology and Earth System Sciences ; Volume 19, Issue 12 , 2015 , Pages 4859-4876 ; 10275606 (ISSN) ; Ahmadi, M ; Gates, T. K ; Arabi, M ; Sharif University of Technology
Copernicus GmbH
2015
Abstract
Elevated levels of nitrate (NO3) in groundwater systems pose a serious risk to human populations and natural ecosystems. As part of an effort to remediate NO3 contamination in irrigated stream-aquifer systems, this study elucidates agricultural and environmental parameters and processes that govern NO3 fate and transport at the regional (500 km2), local (50 km2), and field scales (<1 km2). Specifically, the revised Morris sensitivity analysis method was applied to a finite-difference nitrogen cycling and reactive transport model of a regional-scale study site in the lower Arkansas River valley in southeastern Colorado. The method was used to rank the influence of anthropogenic activities and...
A new study in designing MTMDs in SDOF and MDOF systems based on the spectral analysis method
, Article Earthquake and Structures ; Volume 19, Issue 4 , 2020 , Pages 243-259 ; Shargh, F. H ; Rofooei, F. R ; Sharif University of Technology
Techno-Press
2020
Abstract
This study aims to optimize, design, and predict the MTMDs performance in SDOF systems using spectral analysis, and then apply their results to MDOF structures. Given the importance of spectral analysis in the design of new engineering structures, achieving a method for designing TMDs based on this theory can be of great importance for structural designers. In this study, several convenient combinations of MTMDs in an SDOF system are first considered to minimize the maximum displacement. For calculating the frequency ratios of dampers, an innovative technique is adopted in which the values of different modal responses obtained from the spectral analysis are approached together. This...
Aniline-silica nanocomposite as a novel solid phase microextraction fiber coating
, Article Journal of Chromatography A ; Volume 1238 , May , 2012 , Pages 22-29 ; 00219673 (ISSN) ; Roostaie, A ; Sharif University of Technology
2012
Abstract
A new unbreakable solid phase microextraction (SPME) fiber coating based on aniline-silica nanocomposite was electrodeposited on a stainless steel wire. The electropolymerization process was carried out at a constant deposition potential, applied to the corresponding aqueous electrolyte containing aniline and silica nanoparticles. The scanning electron microscopy (SEM) images showed the non-smooth and the porous surface structure of the prepared nanocomposite. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some environmentally important polycyclic aromatic hydrocarbons (PAHs), as model compounds, from aqueous samples....
Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples
, Article Analytica Chimica Acta ; Volume 716 , 2012 , Pages 34-39 ; 00032670 (ISSN) ; Aghakhani, A ; Baghernejad, M ; Akbarinejad, A ; Sharif University of Technology
2012
Abstract
A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200nm for polyamide nanofibers with a homogeneous and porous surface...
Novel nanofiber coatings prepared by electrospinning technique for headspace solid-phase microextraction of chlorobenzenes from environmental samples
, Article Analytical Methods ; Volume 3, Issue 6 , Apr , 2011 , Pages 1284-1289 ; 17599660 (ISSN) ; Aghakhani, A ; Sharif University of Technology
2011
Abstract
Novel unbreakable solid phase microextraction (SPME) fiber coatings were fabricated by electrospinning method in which the polymeric solution was converted to nanofibers using high voltages. Four different polymers, polyurethane (PU), polycarbonate (PC), polyamide (PA) and polyvinyl chloride (PVC) were prepared as the fiber coatings on thin stainless steel wires. The extraction efficiencies of new coatings were investigated by headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorobenzenes from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Among them, PU showed a prominent efficiency. Effects of coating time and polymer...
Toward a comprehensive microextraction/determination unit: A chip silicon rubber polyaniline-based system and its direct coupling with gas chromatography and mass spectrometry
, Article Journal of Separation Science ; Volume 39, Issue 21 , 2016 , Pages 4227-4233 ; 16159306 (ISSN) ; Allahdadlalouni, M ; Zamani, C ; Sharif University of Technology
Wiley-VCH Verlag
2016
Abstract
An inexpensive silicon rubber-based chip was constructed by fabricating a triangle-shaped microcanal with a 135 μm width and 234 μm depth by laser ablation technique. The fabricated groove was sealed by a thin glass cover while two pieces of stainless-steel tubing were connected to each side of the canal. Then, a thin polyaniline film was synthesized on the walls of the canal by chemical oxidation using a syringe pump to deliver the relevant reagents. The microfluidic system was eventually connected to a gas chromatography-mass spectrometry. To evaluate the capability of the constructed microfluidic system, it was implemented to the analysis of submilliliter volumes of environmental samples...
A metal organic framework-polyaniline nanocomposite as a fiber coating for solid phase microextraction
, Article Journal of Chromatography A ; Volume 1431 , 2016 , Pages 27-35 ; 00219673 (ISSN) ; Javanmardi, H ; Abbasi, A ; Banihashemi, S ; Sharif University of Technology
Elsevier B. V
Abstract
A metal organic framework-polyaniline (MOF/PANI) nanocomposite was electrodeposited on a stainless steel wire and used as a solid phase microextraction (SPME) fiber coating. The electropolymerization process was carried out under a constant deposition potential and applied to the corresponding aqueous electrolyte containing aniline and MOF particles. The employment of MOFs with their large and small cages and 3-D structures in synthesizing a nanocomposite was assumed to be efficient constitutes to induce more non-smooth and porous structures, approved by scanning electron microscopy (SEM) images. Three different MOFs were incorporated to synthesize the desired nanocomposites and the...
On the effects of hydrostatic stress on Li diffusion kinetics and stresses in spherical active particles of Li-ion battery electrodes
, Article Mechanics of Materials ; Volume 137 , 2019 ; 01676636 (ISSN) ; Arghavani, J ; Naghdabadi, R ; Sharif University of Technology
Elsevier B.V
2019
Abstract
The main process in lithium-ion batteries is insertion/extraction of lithium into/from active electrode particles. Some active material of lithium-ion battery electrodes experiences a large volume change due to changes in lithium concentration. Since the failure of the electrode might be caused by large stresses, the mechanical phenomena in the electrode which are associated with the insertion and extraction of lithium, are of particular importance. This paper establishes an integrated framework of balance laws and thermodynamically consistent equations which couples lithium diffusion with a small elastic deformation. We investigate the effect of hydrostatic stress on lithium diffusion and...
An investigation of fracture geometry in hydraulic fracturing on a gas reservoir well production enhancement
, Article Petroleum Science and Technology ; Vol. 32, issue. 2 , 2014 , pp. 150-157 ; ISSN: 10916466 ; Parvazdavani, M ; Abbasi, S ; Rahnama, A. R ; Sharif University of Technology
Abstract
Utilizing improved production methods have been always challenging in upstream industries. Nowadays, hydraulic fracturing is one of the most prestigious mechanical methods. Application of this method is in wells with low productivity index. Hydraulic fracturing efficiency depends on various factors, such as fracture geometry, fluid composition, and stress distribution. But some of them would be ignored, such as fracture geometry, which is neglected due to nongravity and lack of investigation of DFN statistical population assumption. The authors develop a more comprehensive methodology based on fracture geometry and aim to model one of the gas reservoirs in Iran that is naturally fractured by...
The effect of MPL permeability on water fluxes in PEM fuel cells: Experimental verification
, Article ECS Transactions, 9 October 2011 through 14 October 2011 ; Volume 41, Issue 1 , 2011 , Pages 521-538 ; 19385862 (ISSN) ; 9781607682547 (ISBN) ; Sharif University of Technology
2011
Abstract
The distribution of water fluxes is strongly influenced by the properties of the media adjacent to the cathode catalyst layer (CCL), viz. polymer electrolyte membrane (PEM) and gas diffusion media (GDM). We propose a model that is applied under varying humidification of the cathode feed gas, with water removal in liquid and vapor form. The model warrants the definition of a critical current density up to which water removal out of the CCL could proceed completely via vapor diffusion to the cathode side. Above the critical current density, excessive water generation leads to the build-up of an excess liquid pressure in the CCL, which drives hydraulic fluxes to PEM and GDM sides. Experimental...
Anaerobic digestion of vegetable waste
, Article Chemical Engineering Transactions ; Volume 24 , 2011 , Pages 1291-1296 ; 19749791 (ISSN) ; Shayegan, J ; Sharif University of Technology
Italian Association of Chemical Engineering - AIDIC
2011
Abstract
Fruit and vegetable wastes are produced in large quantities in Iran, and constitute a source of nuisance in municipal landfills. The objective of this study was to optimize the applications of anaerobic digestion for the treatment of municipal organic wastes. We studied the effect of organic loading rates on anaerobic digestion of vegetable wastes. The complete-mix, pilot-scale digester with working volume of 70 1 was used. The experiments were conducted at 34°C with a fixed hydraulic retention time of 25 days. The digester was operated at different organic feeding rates of 1.4, 2 and 2.75 kg VS/(m3.d). The biogas produced had methane composition of 49.7- 64% and biogas production rates of...
Capture zone of a partially penetrating well with skin effects in confined aquifers
, Article Transport in Porous Media ; Volume 91, Issue 2 , January , 2012 , Pages 437-457 ; 01693913 (ISSN) ; Shafei, B ; Rashidian Dezfouli, H ; Mohamadzadeh, M ; Sharif University of Technology
2012
Abstract
The analysis of the capture zone of wells is useful to design pumping systems and wellhead protection programs. In this study, an analytical solution for the head distribution of a partially penetrating well, and semi-analytical methods to determine the geometry of the capture surface are presented. The analytical solution is derived based on an infinitesimal radius under a constant pumping rate in a two-zone confined aquifer. Using the developed solution, a sensitivity analysis is performed to study the influence of skin on the drawdown, location of the stagnation point, maximum horizontal and vertical extent of the capture surface. The results show the efficiency of a partially penetrating...
Elitist continuous ant colony optimization algorithm for optimal management of coastal aquifers
, Article Water Resources Management ; Volume 25, Issue 1 , 2010 , Pages 165-190 ; 09204741 (ISSN) ; Ketabchi, H ; Sharif University of Technology
2010
Abstract
This paper presents an evolutionary based approach to achieve optimal management of a coastal aquifer to control saltwater intrusion. An improved Elitist Continuous Ant Colony Optimization (ECACO) algorithm is employed for optimal control variables setting of coastal aquifer management problem. The objectives of the optimal management are; maximizing the total water-pumping rate, while controlling the drawdown limits and protecting the wells from saltwater intrusion. Since present work is one of the first efforts towards the application of an ECACO algorithm, sharp interface solution for steady state problem is first exploited. The performance of the developed optimization model is evaluated...
Experimental investigation of clear-water local scour of compound piers
, Article Journal of Hydraulic Engineering ; Volume 136, Issue 6 , June , 2010 , Pages 343-351 ; 07339429 (ISSN) ; Baratian Ghorghi, Z ; Beheshti, A. A ; Sharif University of Technology
2010
Abstract
Local scour around complex piers under steady clear-water condition was studied experimentally for a variety of configuration, including different sizes and shapes of complex piers. A total of 70 experiments were carried out. Three sets of experiments were performed over the entire range of possible pile cap elevations for complex piers with different geometrical characteristics. The collected data are used to quantify the pile cap elevations that maximize or minimize the local scour depth. Some of the available methodologies to estimate the maximum local scour depth around such complex piers are evaluated. The predictions of the scour depths improved by using the revised methods of...
MODSharp: Regional-scale numerical model for quantifying groundwater flux and contaminant discharge into the coastal zone
, Article Environmental Modelling and Software ; Volume 22, Issue 9 , 2007 , Pages 1307-1315 ; 13648152 (ISSN) ; Sharif University of Technology
2007
Abstract
In this paper the development of a quasi-three-dimensional numerical model that can be used for quantifying groundwater inputs and associated contaminant discharged from coastal aquifers into the coastal zone at a regional scale is presented. The present model is called MODSharp. In order to handle problems at a regional scale, the sharp interface approach which is used for conceptualising seawater intrusion, is applied to this model. This model can be used for the simulation of groundwater flow and contaminant transport in layered coastal aquifers at a regional scale. The method of characteristics is used to solve the advection-dispersion equation, which governs contaminant transport in...
A stable moving-particle semi-implicit method for free surface flows
, Article Fluid Dynamics Research ; Volume 38, Issue 4 , 2006 , Pages 241-256 ; 01695983 (ISSN) ; Farhadi, L ; Sharif University of Technology
2006
Abstract
In this paper, a mesh-less numerical approach is utilized to solve Euler's equation that is the governing equation of the irrotational flow of ideal fluids. A fractional step method of discritization is applied which consists to split each time step in two steps. This numerical method is based on moving-particle semi-implicit method (MPS) for simulating incompressible inviscid flows with free surfaces. The motion of each particle is calculated through interactions with neighboring particles covered with the kernel function. There are limitations for getting a stable solution by MPS method. In this paper, various kernel functions are considered and applied to improve the stability of MPS...