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hydraulics
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Total 337 records
Design for Fabrication of a Knee Prosthesis Wear Simulator
, M.Sc. Thesis Sharif University of Technology ; Durali, Mohammad (Supervisor)
Abstract
Total knee replacement surgery is the most common joint replacement in the world. Considering the increasing rate of this procedure and costs and difficulties of the repeated operation, many efforts have been made to improve the performance and lifetime of implants. The Polyethylene component of the implant is the most prone component to fail due to wear. To evaluate new knee prosthesis designs, it is necessary to have a wear test simulator. Objective of this project is to detail design a knee prosthesis wear simulator according to ISO 14243 in order to investigate the performance of prosthesises in long term and under in-vivo conditions. During this project, studies have been made to get...
Impact of Stress on Permeability of Packed Hydraulic Fracture
, M.Sc. Thesis Sharif University of Technology ; Shad, Saeed (Supervisor) ; Fatemi, Mobeen ($item.subfieldsMap.e)
Abstract
Given the broad role of oil and gas playing in the world economy, finding the hydrocarbon reservoir that economically is affordable is quite significant. Some of the unconventional oil and gas reservoirs are important from the economic point of view since they produce insufficient hydrocarbon due to either low permeability or damage during drilling and production. Hydraulic fracturing is one of the most significant methods for improving the productivity of wells and reservoirs. Hydraulic fracturing acts by affecting on reservoir rock physic. In the current century, this approach has an essential effect in enhancing the permeability and production of reservoirs by creating, extending and...
Effect of DEM Resolution on Hydraulic Modeling of Flood Inundation Area: Case Study of Gorganrood River, Northeast of Iran
, M.Sc. Thesis Sharif University of Technology ; Ataie Ashtiani, Behzad (Supervisor)
Abstract
Digital Elevation Models (DEM) is a crucial element of hydraulic models, including floods. Due to the lack of high-precision topographic data, including ground-based mapping hydraulic modeling is challenging. In recent years, remote sensing data, extensively used by many researchers in hydraulic modeling due to global coverage and free access. One of the most critical questions in hydraulic modeling is the efficiency of these DEMs in flood simulation. This research focused on using remote-sensing-based DEMs, such as SRTM-30m and 90m, ASTER-30m, and ALOS-12.5m DEMs, on the performance of the HEC-RAS-2D model in the Gorganrood river.The results showed that ALOS and SRTM-30m DEMs' accuracy and...
Development of a New Analytical Model based on Soil-water Retention Curve Microstructure Considering the Effects of Osmotic Potential
, M.Sc. Thesis Sharif University of Technology ; Sadeghi, Hamed (Supervisor)
Abstract
The soil-water retention curves (SWRC) is an unsaturated soil mechanics hydro chemical state surface, which expresses the relationship between the soil suction and water content. The soil-water retention curve could describe the water adsorption and desorption process that happened in soils. The difference between the desorption or drying retention curve and the adsorption or wetting retention curves in a specific soil specimen indicates the hydraulic hysteresis phenomenon. Generally, the amount of water remaining in the drying process is greater than the amount of water adsorbed in the wetting process at a certain amount of suction. Suction due to the combined effects of capillary and...
Numerical Modeling of Solid Transport in a Transparent Fracture
, M.Sc. Thesis Sharif University of Technology ; Shad, Saeed (Supervisor) ; Zivar, Davood (Co-Supervisor)
Abstract
Hydraulic fracturing, as an industry-leading technology, has proven to be very efficient in increasing the productivity of oil and gas wells. Therefore, this technology has been taken into attention in recent years and the number of hydraulic fracturing operations has been increasing. In order to enhance the efficiency of this technology, the final transmissibility of the fracture needs to be at the maximum possible value. To do so, proppant injection is the most common way to maintain a fracture open. To achieve a successful hydraulic fracture operation, detailed knowledge of the particle's transport and distribution inside the fracture is needed.In this study, a static fracture geometry...
Analysis and Optimization of Plug Slips for Oil Well Formation Fracturing
, M.Sc. Thesis Sharif University of Technology ; Arghavani Hadi, Jamal (Supervisor)
Abstract
In the oil industry, after drilling an oil well and laying pipes, it is time for the hydraulic fracturing process. In the process of hydraulic fracturing, a fracture must be created in the casing pipe of the well. The reason for this is that the oil from the existing reservoir enters the well so that it can be extracted. The end of the well must be blocked to cause a fracture in the well body. The reason is that after creating a fracture in the casing pipe, proppant particles are pumped together with water inside the well to keep it open. For the proppant particles to be placed inside the cracks, it is necessary to create pressure in the fracture area. To create pressure in the fracture area...
Technical note Variable moderation high performance light water reactor (VMHWR)
, Article Annals of Nuclear Energy ; Volume 58 , 2013 , Pages 1-5 ; 03064549 (ISSN) ; Tashakor, S ; Salehi, A. A ; Abbaspour Tehrani Fard, A ; Sharif University of Technology
2013
Abstract
A new flow model of high performance light water reactor (HPLWR) is discussed in the present study. HPLWR involves a negative density reactivity coefficient with high time delay. This factor decreases the stability of such reactors when transient and abnormal accidents happen. A new design for enhancing safety and efficiency in such reactors is presented. In the new design, the fluid passing through the moderator channels and the assembly gaps (known as a moderator) flows in channels detached from coolants. It is possible to control the moderator mass flux. Increasing or decreasing the moderator mass flux will modify the moderation capacity, which results in a change in the reactor power....
System and method for analysis of involving factors in the demisting cyclone efficiency
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), San Diego, CA ; Volume 15 , November , 2013 ; 9780791856444 (ISBN) ; Ehteram, M. A ; Ahmadian, M. T ; Barari, A ; ASME ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2013
Abstract
In this study a system for real-time analysis of some involving factors in the efficiency of gas-liquid separators is developed based on the weighing method. An ultrasonic atomizer generates water drops in a size range of 1-10 μm with the same frequency during the test. A cyclone separator is selected and effect of the developing flow rate and shape of the mini-riser as a part of connecting assembly to the cyclone separator is investigated. Further an efficient electrostatic precipitator (ESP) with outcome of single-phase airflow is employed in the downstream of the cyclone to separate remaining droplets and produce the same pressure loss during the test. Circular, triangular, rectangular...
Neutronic analysis of HPLWR fuel assembly cluster
, Article Annals of Nuclear Energy ; Volume 50 , December , 2012 , Pages 38-43 ; 03064549 (ISSN) ; Salehi, A. A ; Jahanfarnia, G ; Abbaspour Tehrani Fard, A ; Sharif University of Technology
2012
Abstract
In the present study the neutronic analysis of fuel assembly cluster of the HPLWR is discussed. Neutronic calculations are performed using WIMS-D4 and CITATION codes. Thermal-hydraulic code containing the properties and specifications of the fuel assembly of HPLWR is utilized. The calculated axial power in each selected control volume is used in the thermal-hydraulic code to get the properties of the fluid and fuel needed for further neutronic analysis. The process of coupling continues until convergence is achieved. Finally, the obtained neutronic results including axial power distribution, neutron flux, and power peaking factors are discussed in the present article
A new method to calculate efficiency of randomly-packed distillation columns and its comparison with the methods utilized in ASPEN Plus
, Article Fuel Processing Technology ; Volume 96 , 2012 , Pages 65-73 ; 03783820 (ISSN) ; Sadeghifar, A ; Sharif University of Technology
2012
Abstract
In this paper, a unique and applicable method was developed for calculation of efficiency (and mass and heat transfer coefficients) of randomly-packed distillation columns. This method has potential advantages; e.g., unlike all the available methods, it can calculate efficiency without using any empirical mass transfer and hydraulic correlations, and without the need to estimate the operational and hydraulic parameters of an operating column. It, therefore, will be free of errors and limitations of such empirical items and can be used for efficiency calculation of any random packing including new ones. Along with an analysis of the proposed method, the paper also presents a thorough analysis...
Manifold coarse graining for online semi-supervised learning
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 5 September 2011 through 9 September 2011 ; Volume 6911 LNAI, Issue PART 1 , September , 2011 , Pages 391-406 ; 03029743 (ISSN) ; 9783642237799 (ISBN) ; Shaban, A ; Rabiee, H. R ; Rohban, M. H ; Sharif University of Technology
2011
Abstract
When the number of labeled data is not sufficient, Semi-Supervised Learning (SSL) methods utilize unlabeled data to enhance classification. Recently, many SSL methods have been developed based on the manifold assumption in a batch mode. However, when data arrive sequentially and in large quantities, both computation and storage limitations become a bottleneck. In this paper, we present a new semi-supervised coarse graining (CG) algorithm to reduce the required number of data points for preserving the manifold structure. First, an equivalent formulation of Label Propagation (LP) is derived. Then a novel spectral view of the Harmonic Solution (HS) is proposed. Finally an algorithm to reduce...
Hydraulic performance of drain pipe in a submerged tank
, Article Urban Water Management: Challenges and Oppurtunities - 11th International Conference on Computing and Control for the Water Industry, CCWI 2011, 5 September 2011 through 7 September 2011, Exeter ; Volume 1 , 2011 ; 0953914089 (ISBN) ,9780953914081 (ISBN) ; Mahmoud Borghei, S ; Sharif University of Technology
2011
Abstract
The hydraulic performances of drain pipes are very important in drainage projects and systems. Usually these pipes are used in a saturated soil to decrease the water table to a favorable level or, drain the excess water. However, drain pipes can be used in a water or wastewater tank for different purposes such as selective withdrawal. There are not much published documents on the performance of drain pipes in submerged situations. Therefore, the aim of this study was to examine the performance of drain pipe in a submerged tank. For this, a horizontal pipe of 26.5 mm inner diameter, 5 meter long with 48 circular drain inlets of 10 mm diameter at equal distances along the pipe have been tested...
An applicable method for efficiency estimation of operating tray distillation columns and its comparison with the methods utilized in HYSYS and Aspen Plus
, Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 51, Issue 10 , October , 2015 , Pages 1393-1402 ; 09477411 (ISSN) ; Sharif University of Technology
Springer Verlag
2015
Abstract
Developing general methods that rely on column data for the efficiency estimation of operating (existing) distillation columns has been overlooked in the literature. Most of the available methods are based on empirical mass transfer and hydraulic relations correlated to laboratory data. Therefore, these methods may not be sufficiently accurate when applied to industrial columns. In this paper, an applicable and accurate method was developed for the efficiency estimation of distillation columns filled with trays. This method can calculate efficiency as well as mass and heat transfer coefficients without using any empirical mass transfer or hydraulic correlations and without the need to...
Investigating the propagation noise in PWRs via closed-loop neutron-kinetic/thermal-hydraulic noise calculations
, Article Annals of Nuclear Energy ; Volume 80 , 2015 , Pages 101-113 ; 03064549 (ISSN) ; Vosoughi, N ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Neutron noise induced by propagating thermal-hydraulic disturbances (propagation noise for short) in pressurized water reactors is investigated in this paper. A closed-loop neutron-kinetic/thermal-hydraulic noise simulator (named NOISIM) has been developed, with the capability of modeling the propagation noise in both Western-type and VVER-type pressurized water reactors. The neutron-kinetic/thermal-hydraulic noise equations are on the basis of the first-order perturbation theory. The spatial discretization among the neutron-kinetic noise equations is based on the box-scheme finite difference method (BSFDM) for rectangular-z, triangular-z and hexagonal-z geometries. Furthermore, the finite...
Distinguishing attack on bivium
, Article Proceedings - 10th IEEE International Conference on Computer and Information Technology, CIT-2010, 7th IEEE International Conference on Embedded Software and Systems, ICESS-2010, ScalCom-2010, 29 June 2010 through 1 July 2010, Bradford ; 2010 , Pages 1075-1078 ; 9780769541082 (ISBN) ; Rohani, N ; Mohajeri, J ; Aref, M. R ; Sharif University of Technology
2010
Abstract
Bivium is a simplified version of Trivium, a hardware profile finalist of eSTREAM project. Bivium has an internal state of size 177 bits and a key length of 80 bits. In this paper we introduce a distinguishing attack on this cipher. In this method we first find the best linear approximation for the updating function. Then by using this approximation, and optimizing the time delay, we find the distinguisher. The complexity of the attack is O(230.79), which is an improvement to the previous distinguishing attack with a complexity of order O(232)
High-throughput stream categorization and intrusion detection on GPU
, Article 8th ACM/IEEE International Conference on Formal Methods and Models for Codesign, MEMOCODE 2010, 26 July 2010 through 28 July 2010 ; August , 2010 , Pages 81-84 ; 9781424478859 (ISBN) ; Eslamiy, H ; Totoniy, E ; Khademy, A ; Sharif University of Technology
Abstract
We present a design and implementation of a high-throughput deep packet inspection performing both stream categorization and intrusion detection on GPU platform using CUDA. This implementation is capable of matching 64 ethernet packet streams against 25 given regular expressions at 524 Mb/s rate on a computer system with GeForce GTX 295 graphic card
A steady-state saturation model to determine the subsurface travel time (STT) in complex hillslopes
, Article Hydrology and Earth System Sciences ; Volume 14, Issue 6 , Jun , 2010 , Pages 891-900 ; 10275606 (ISSN) ; Talebi, A ; Ardakanian, R ; Shamsai, A ; Sharif University of Technology
2010
Abstract
The travel time of subsurface flow in complex hillslopes (hillslopes with different plan shape and profile curvature) is an important parameter in predicting the subsurface flow in catchments. This time depends on the hillslopes geometry (plan shape and profile curvature), soil properties and climate conditions. The saturation capacity of hillslopes affect the travel time of subsurface flow. The saturation capacity, and subsurface travel time of compound hillslopes depend on parameters such as soil depth, porosity, soil hydraulic conductivity, plan shape (convergent, parallel or divergent), hillslope length, profile curvature (concave, straight or convex) and recharge rate to the groundwater...
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...
A practical distinguisher for the Shannon cipher
, Article Journal of Systems and Software ; Volume 83, Issue 4 , 2010 , Pages 543-547 ; 01641212 (ISSN) ; Mohajeri, J ; Salmasizadeh, M ; Hakala, R. M ; Nyberg, K ; Sharif University of Technology
Abstract
In this paper, we present a practical linear distinguisher on the Shannon stream cipher. Shannon is a synchronous stream cipher that uses at most 256-bit secret key. In the specification for Shannon, designers state that the intention of the design is to make sure that there are no distinguishing attacks on Shannon requiring less than 280 keystream words and less than 2128 computations. In this work we use the Crossword Puzzle attack technique to construct a distinguisher which requires a keystream of length about 231 words with workload about 231
An X-FEM implementation of hydro-fracture growth in naturally fractured saturated porous media
, Article Poromechanics 2017 - Proceedings of the 6th Biot Conference on Poromechanics, 9 July 2017 through 13 July 2017 ; 2017 , Pages 2027-2034 ; 9780784480779 (ISBN) ; Khoei, A. R ; Khalili, N ; Sharif University of Technology
Abstract
In this paper, a coupled hydro-mechanical formulation is developed for the simulation of interaction between hydraulic fractures and natural discontinuities within saturated porous media. The momentum balance equation of the bulk together with the momentum balance and continuity equations of the fluid phase are employed to obtain the fully coupled set of governing equations. The hydro-fracture is modeled for fluid flow using the Darcy law. The natural discontinuity on the other hand is modeled for both opening and closing modes which induce fluid flow and/or contact behavior along the crack edges. The discontinuity in the displacement field is incorporated by using the Heaviside enrichment...