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    Design and Fabrication of an Optimized Wake Equalizing Duct in Order to Improve Propulsion System Operation

    , M.Sc. Thesis Sharif University of Technology Ali Mirzazadeh, Siamak (Author) ; Seif, Mohammad S (Supervisor) ; Rad, Manouchehr ($item.subfieldsMap.e)
    Abstract
    Special geometrical sections, known as “duct”, which can be installed on merchant vessels stern in order to improve propulsion system and propeller performance, today have evolved considerably. The force which produces by the propeller depends on efficiency of propulsion system. In the way of improving the efficiency of propulsion systems, by using these special geometrical sections, to much research have been done from the mid-twentieth century. The Wake Equalizing Ducts (WEDs) in addition to conduct the more uniform fluid flow to the propeller disk (which causes to improve the propeller operation), affect on flow separation in ship stern zone and will decrease the separated flow zone.... 

    Sustainable Analysis of Unions Uses Axiomatic Design Theory with Focus on European Union

    , M.Sc. Thesis Sharif University of Technology Torbati, Mostafa (Author) ; Malaek, S. M (Supervisor)
    Abstract
    In this project, we examine the stability or sustainability issue in unions, in other words we want to know whether integration in European Union is stable? Countries have positive attitude toward unions and being member in unions is at special priorities. The main reason for countires is improve economy and national Security.
    The main question in this research is modeling European Union with Axiomatic Design Theory and analysis of sustainability based on this theory. This study has attempted to push Axiomatic Design Theroy in the new field of Systems Engineering and also it gives a new and differnet approach to stability.
     

    Using Body Fluids for Early Prostate Cancer Detection

    , M.Sc. Thesis Sharif University of Technology Jalali Dowlatshahi, Sayeh (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor)
    Abstract
    Today, despite the notable progress in diagnostics and therapeutics, cancer remains the second cause of death worldwide. This rather high mortality rate is often attributed to cancers diagnosed at late stages, including prostate cancer. Among the techniques approved for prostate cancer diagnosis, total or free prostate-specific antigen screening using blood serum samples is the sole method able to detect prostate cancer at an early stage. This test has led to a significant decrease in prostate cancer-related deaths. Nonetheless, it possesses several drawbacks, such as the complex, costly, and time-consuming conventional methods utilized in clinical laboratories to assess the concentration of... 

    The importance of electron correlation in graphene and hydrogenated graphene

    , Article European Physical Journal B ; Volume 88, Issue 10 , October , 2015 ; 14346028 (ISSN) Hadipour, H ; Jafari, S. A ; Sharif University of Technology
    springer berlin  2015
    Abstract
    Local density approximation (LDA) and Green function effective Coulomb (GW) calculations are performed to investigate the effect of electronic correlations on the electronic properties of both graphene and graphane. The size of band gap in graphane increases from 3.7 eV in LDA to 4.9 eV in GW approximation. By calculating maximally localized Wannier wave functions, we evaluate the necessary integrals to get the Hubbard U and the exchange J interaction from first principles for both graphene and graphane. Our ab-initio estimates indicate that in the case of graphene, in addition to the hopping amplitude t ∼ 2.8 eV giving rise to the Dirac nature of low lying excitations, the Hubbard U value... 

    Investigation of cervical spine curvature in females with postural neck pain

    , Article Journal of Zanjan University of Medical Sciences and Health Services ; Volume 25, Issue 110 , 2017 , Pages 110-119 ; 16069366 (ISSN) Salahzadeh, Z ; Maroufi, N ; Ahmadi, A ; Behtash, H ; Hazhir Sahneh, S ; Parnianpour, M ; Sharif University of Technology
    Zanjan University of Medical Sciences and Health Services  2017
    Abstract
    Background and Objective: Changes in the cervical spine curvature leads to increased shear force and compression stress on cervical spine and axial loading in different cervical segments. The objective of this study was to compare the general and segmental curvature in the upper and lower cervical spine of women with postural neck pain and Forward Head Posture (FHP), women without neck pain but with FHP and healthy women. Material and Methods: 45 women were divided into three groups: 15 women with postural neck pain and FHP, 15 women without neck pain but with FHP and 15 healthy women. Photography was used to assess neck posture while cervical spine curvature was measured using fluoroscopy... 

    Evaluation of the effects of fullerene c60 nanoparticles on oxidative stress parameters in normal rats liver and brain

    , Article Journal of Advances in Medical and Biomedical Research ; Volume 27, Issue 124 , 2019 , Pages 8-15 ; 26766264 (ISSN) Namadr, F ; Bahrami, F ; Bahri, Z ; Ghanbari, B ; Elahi, S. A ; Mohammadi, M. T ; Sharif University of Technology
    Zanjan University of Medical Sciences and Health Services  2019
    Abstract
    Background & Objective: The potent antioxidant property of fullerene C60 nanoparticles and their derivatives has been demonstrated in a wide range of in vitro and in vivo studies. Hence, we examined the effects of fullerene C60 on the oxidative stress parameters in brain and liver of the rats in normal situation. Materials & Methods: The study was performed in two groups of Wistar rats (each group, n = 6); normal and fullerene-treated normal animals. Treated rats received fullerene via oral gavage at dose of 1 mg/kg/day for 60 days. At termination of the study, the oxidative stress parameters were determined in brain and liver tissues, including the contents of glutathione (GSH) and... 

    Towards a calculus for nondeterministic schemas in Z

    , Article International Journal of Software Engineering and Knowledge Engineering ; Volume 22, Issue 6 , September , 2012 , Pages 839-865 ; 02181940 (ISSN) Haghighi, H ; Mirian Hosseinabadi, S. H ; Sharif University of Technology
    World Scientific  2012
    Abstract
    In our previous work, we presented a Z-based formalism, called NZ, by which one can explicitly specify bounded, unbounded, erratic, angelic, demonic, loose, strict, singular, and plural nondeterminism. The NZ notation is mainly based on a new notion of operation schemas, called multi-schema. Since the operations of the Z schema calculus do not work on multi-schemas anymore, in this paper we augment NZ with a new set of schema calculus operations that can be applied on multi-schemas as well as ordinary operation schemas. To demonstrate the usability of the resulting formalism, we show how this formalism can assist to model game-like situations and concurrent systems as two well-known classes... 

    The coloring of the cozero-divisor graph of a commutative ring

    , Article Discrete Mathematics, Algorithms and Applications ; Volume 12, Issue 3 , 2020 Akbari, S ; Khojasteh, S ; Sharif University of Technology
    World Scientific  2020
    Abstract
    Let R be a commutative ring with unity. The cozero-divisor graph of R denoted by Γ′(R) is a graph with the vertex set W*-(R), where W*-(R) is the set of all nonzero and non-unit elements of R, and two distinct vertices a and b are adjacent if and only if a*‰Rb and b*‰Ra. Let ω(Γ′(R)) and χ(Γ′(R)) denote the clique number and the chromatic number of Γ′(R), respectively. In this paper, we prove that if R is a finite commutative ring, then Γ′(R) is perfect. Also, we prove that if R is a commutative Artinian non-local ring and ω(Γ′(R)) is finite, then χ(Γ′(R)) = ω(Γ′(R)). For Artinian local ring, we obtain an upper bound for the chromatic number of cozero-divisor graph. Among other results, we... 

    Parametric study of droplet formation and characteristics within microfluidic devices - A case study

    , Article International Journal of Applied Mechanics ; Volume 12, Issue 7 , 2020 Salehi, S. S ; Shamloo, A ; Kazemzadeh Hannani, S ; Sharif University of Technology
    World Scientific  2020
    Abstract
    Droplet-based microfluidics technologies hold great attention in a wide range of applications, including chemical analysis, drug screening, and food industries. This work aimed to describe the effects of different physical properties of the two immiscible phases on droplet formation in a flow-focusing microfluidic device and determining proper flow rates to form a droplet within the desired size range. A numerical model was developed to solve the governing equations of two-phase flow and the results were validated with previous experimental results. The results demonstrate different types of droplet formation regimes from dripping to jetting and different production rates of droplets as a... 

    Characterization of magnetized CNT-based hybrid nanofluid subjected to convective phenomenon

    , Article International Journal of Modern Physics B ; Volume 35, Issue 28 , 2021 ; 02179792 (ISSN) Hayat, T ; Khan, W. A ; Aqsa ; Waqas, M ; Abbas, S. Z ; Malik, M. Y ; Alqahtani, A. S ; Sharif University of Technology
    World Scientific  2021
    Abstract
    Hybrid nanofluid gains attention of scientists due to its dynamic properties in various fields, and thus, hybrid nanofluids can be taken as an innovative form of nanofluids. Even though analysts acquire tremendous results in the field of hybrid nanofluids but yet no study has been carried out to predict magnetohydrodynamic effects in such fluid models. In this present analysis, influence of MHD has been investigated for the micro hybrid nanofluid over a stretched surface under convective conditions. Combine boundary layer equations for the flow have been altered into a suitable form via boundary layer approximations. Further, complete nonlinear system of equations has been numerically solved... 

    Close stellar encounters kicking planets out of habitable zone in various stellar environments

    , Article International Journal of Modern Physics D ; Volume 30, Issue 9 , 2021 ; 02182718 (ISSN) Bojnordi Arbab, B ; Rahvar, S ; Sharif University of Technology
    World Scientific  2021
    Abstract
    Continuous habitability of a planet is a critical condition for advanced forms of life to appear, but it can be endangered by astronomical events such as stellar encounters. The purpose of this study is to analyze close stellar encounters able to change planetary orbits initially in circumstellar habitable zones and to investigate the expected encounter rates in a variety of stellar environments. Using gravitational simulations for three-body systems, this study analyzed the dependencies of encounter impact-parameters with kinematic, geometric, and habitability parameters of the system. We also used kinematic properties of various stellar regions and estimated encounter rates of the events.... 

    Automated analysis of karyotype images

    , Article Journal of Bioinformatics and Computational Biology ; Volume 20, Issue 3 , 2022 ; 02197200 (ISSN) Khazaei, E ; Emrany, A ; Tavassolipour, M ; Mahjoubi, F ; Ebrahimi, A ; Motahari, S. A ; Sharif University of Technology
    World Scientific  2022
    Abstract
    Karyotype is a genetic test that is used for detection of chromosomal defects. In a karyotype test, an image is captured from chromosomes during the cell division. The captured images are then analyzed by cytogeneticists in order to detect possible chromosomal defects. In this paper, we have proposed an automated pipeline for analysis of karyotype images. There are three main steps for karyotype image analysis: image enhancement, image segmentation and chromosome classification. In this paper, we have proposed a novel chromosome segmentation algorithm to decompose overlapped chromosomes. We have also proposed a CNN-based classifier which outperforms all the existing classifiers. Our... 

    Cross-matching of OGLE III and GAIA catalogues: Investigation of dark-lens microlensing candidates

    , Article International Journal of Modern Physics D ; Volume 31, Issue 7 , 2022 ; 02182718 (ISSN) Dehghani, A ; Rahvar, S ; Sharif University of Technology
    World Scientific  2022
    Abstract
    In this work, we use 13 microlensing candidates with dark lenses from OGLE III catalogue [L. Wyrzykowski et al., Mon. Not. R. Astron. Soc. 458 (2016) 3012.] and cross-match them with the GAIA catalogue. We identify the microlensing source stars in the GAIA catalogue by comparing the coordinate and the magnitude of stars and using the proper motion and the parallax parameters of the source stars. Combining with the microlensing light curves as well as the microlensing parallax effect, we determine the mass and the distance of lenses from Earth. We conclude that the lens for this set of microlensing events for the massive lenses are black hole and for the small lenses are neutron/white dwarf... 

    Star chromatic number of some graphs

    , Article Discrete Mathematics, Algorithms and Applications ; Volume 14, Issue 1 , 2022 ; 17938309 (ISSN) Akbari, S ; Chavooshi, M ; Ghanbari, M ; Taghian, S ; Sharif University of Technology
    World Scientific  2022
    Abstract
    A proper vertex coloring of a graph G is called a star coloring if every two color classes induce a forest whose each component is a star, which means there is no bicolored P4 in G. In this paper, we show that the Cartesian product of any two cycles, except C3C3 and C3C5, has a 5-star coloring. © 2022 World Scientific Publishing Company  

    Nonlinear free vibration analysis of in-plane Bi-directional functionally graded plate with porosities resting on elastic foundations

    , Article International Journal of Applied Mechanics ; Volume 14, Issue 1 , 2022 ; 17588251 (ISSN) Hashemi, S ; Shahri, P. K ; Beigzadeh, S ; Zamani, F ; Eratbeni, M. G ; Mahdavi, M ; Heidari, A ; Khaledi, H ; Abadi, M. R. R ; Sharif University of Technology
    World Scientific  2022
    Abstract
    This paper deals with the nonlinear free vibration analysis of in-plane bi-directional functionally graded (IBFG) rectangular plate with porosities which are resting on Winkler-Pasternak elastic foundations. The material properties of the IBFG plate are assumed to be graded along the length and width of the plate according to the power-law distribution, as well as, even and uneven types are taken into account for porosity distributions. Equations of motion are developed by means of Hamilton's principle and von Karman nonlinearity strain-displacement relations based on classical plate theory (CPT). Afterward, the time-dependent nonlinear equations are derived by applying the Galerkin... 

    Wavelet-Based biphase analysis of brain rhythms in automated wake-sleep classification

    , Article International Journal of Neural Systems ; 2022 ; 01290657 (ISSN) Mohammadi, E ; Makkiabadi, B ; Shamsollahi, M. B ; Reisi, P ; Kermani, S ; Sharif University of Technology
    World Scientific  2022
    Abstract
    Many studies in the field of sleep have focused on connectivity and coherence. Still, the nonstationary nature of electroencephalography (EEG) makes many of the previous methods unsuitable for automatic sleep detection. Time-frequency representations and high-order spectra are applied to nonstationary signal analysis and nonlinearity investigation, respectively. Therefore, combining wavelet and bispectrum, wavelet-based bi-phase (Wbiph) was proposed and used as a novel feature for sleep-wake classification. The results of the statistical analysis with emphasis on the importance of the gamma rhythm in sleep detection show that the Wbiph is more potent than coherence in the wake-sleep... 

    Modules with finitely many submodules

    , Article Algebra Colloquium ; Volume 23, Issue 3 , 2016 , Pages 463-468 ; 10053867 (ISSN) Akbari, S ; Khalashi Ghezelahmad, S ; Yaraneri, E ; Sharif University of Technology
    World Scientific Publishing Co. Pte Ltd  2016
    Abstract
    In this paper, we study modules having only finitely many submodules over any ring which is not necessarily commutative. We try to understand how such a module decomposes as a direct sum. We justify that any module V having only finitely many submodules over any ring A is an extension of a cyclic A-module by a finite A-module. Under some assumptions on A, such as commutativity of A, we prove that an A-module V has finitely many submodules if and only if V can be written as a direct sum of a cyclic A-module having only finitely many A-submodules and a finite A-module  

    A fault tolerant parallelism approach for implementing High-throughput pipelined advanced encryption standard

    , Article Journal of Circuits, Systems and Computers ; Volume 25, Issue 9 , 2016 ; 02181266 (ISSN) Mardani Kamali, H ; Hessabi, S ; Sharif University of Technology
    World Scientific Publishing Co. Pte Ltd  2016
    Abstract
    Advanced Encryption Standard (AES) is the most popular symmetric encryption method, which encrypts streams of data by using symmetric keys. The current preferable AES architectures employ effective methods to achieve two important goals: protection against power analysis attacks and high-throughput. Based on a different architectural point of view, we implement a particular parallel architecture for the latter goal, which is capable of implementing a more efficient pipelining in field-programmable gate array (FPGA). In this regard, all intermediate registers which have a role for unrolling the main loop will be removed. Also, instead of unrolling the main loop of AES algorithm, we implement... 

    Codon usage and protein sequence pattern dependency in different organisms: A Bioinformatics approach

    , Article Journal of Bioinformatics and Computational Biology ; Volume 13, Issue 2 , April , 2015 ; 02197200 (ISSN) Foroughmand Araabi, M. H ; Goliaei, B ; Alishahi, K ; Sadeghi, M ; Goliaei, S ; Sharif University of Technology
    World Scientific Publishing Co. Pte Ltd  2015
    Abstract
    Although it is known that synonymous codons are not chosen randomly, the role of the codon usage in gene regulation is not clearly understood, yet. Researchers have investigated the relation between the codon usage and various properties, such as gene regulation, translation rate, translation efficiency, mRNA stability, splicing, and protein domains. Recently, a universal codon usage based mechanism for gene regulation is proposed. We studied the role of protein sequence patterns on the codons usage by related genes. Considering a subsequence of a protein that matches to a pattern or motif, we showed that, parts of the genes, which are translated to this subsequence, use specific ratios of... 

    On the complement of the intersection graph of submodules of a module

    , Article Journal of Algebra and its Applications ; Volume 14, Issue 8 , October , 2015 ; 02194988 (ISSN) Akbari, S ; Tavallaee, H. A ; Khalashi Ghezelahmad, S ; Sharif University of Technology
    World Scientific Publishing Co. Pte Ltd  2015
    Abstract
    Let R be a ring with identity and M be a unitary left R-module. The complement of the intersection graph of submodules of M, denoted by Γ(M), is defined to be a graph whose vertices are in one-to-one correspondence with all nontrivial submodules of M and two distinct vertices are adjacent if and only if the corresponding submodules of M have zero intersection. In this paper, we consider the complement of the intersection graph of submodules of a module. We prove that, if Γ(M) is connected and Δ(Γ(M)) < ∞, then M is semisimple, where Δ(Γ(M)) is the maximum degree of Γ(M). We show that, if Γ(M) is a forest, then each component of Γ(M) is a star graph. Moreover, it is proved that, if Γ(M) is a...