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Dose-dependent effects of nanoscale graphene oxide on reproduction capability of mammals
, Article Carbon ; Volume 95 , December , 2015 , Pages 309-317 ; 00086223 (ISSN) ; Ghaderi, E ; Hashemi, E ; Akbari, E ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
In vivo dose-dependent effects of nanoscale graphene oxide (NGO) sheets on reproduction capability of Balb/C mice were investigated. Biodistribution study of the NGO sheets (intravenously injected into male mice at dose of ∼2000 μg/mL or 4 mg/kg of body weight) showed a high graphene uptake in testis. Hence, in vivo effects of the NGO sheets on important characteristics of spermatozoa (including their viability, morphology, kinetics, DNA damage and chromosomal aberration) were evaluated. Significant in vivo effects was found at the injected concentrations ≥200 μg/mL after (e.g., ∼45% reduction in sperm viability and motility at 2000 μg/mL). Observation of remarkable DNA fragmentations and...
Biometric identification through hand geometry
, Article EUROCON 2005 - The International Conference on Computer as a Tool, Belgrade, 21 November 2005 through 24 November 2005 ; Volume II , 2005 , Pages 1011-1014 ; 142440049X (ISBN); 9781424400492 (ISBN) ; Fatemizadeh, E ; Sharif University of Technology
IEEE Computer Society
2005
Abstract
A new approach for person identification based on hand geometry is presented. After preprocessing hand features are extracted from a photograph taken while user has placed his/her hand (either left or right) on the platform of a document scanner with no limits or fixation. Different pattern recognition techniques like Gaussian mixture modeling (GMM), Radial basis function neural networks (RBF), Multi layer perceptron (MLP), k-Nearest Neighbor (k-NN), Bayes method and mahalanobis/Hamming distance have been used in classification section. Experimental results show a rate of success above 90%. © 2005 IEEE
Ultra-sensitive detection of leukemia by graphene
, Article Nanoscale ; Vol. 6, issue. 24 , Dec , 2014 , p. 14810-14819 ; Ghaderi, E ; Hashemi, E ; Rahighi, R ; Sharif Universit of Technology
2014
Abstract
Graphene oxide nanoplatelets (GONPs) with extremely sharp edges (lateral dimensions ∼20-200 nm and thicknesses <2 nm) were applied in extraction of the overexpressed guanine synthesized in the cytoplasm of leukemia cells. The blood serums containing the extracted guanine were used in differential pulse voltammetry (DPV) with reduced graphene oxide nanowall (rGONW) electrodes to develop fast and ultra-sensitive electrochemical detection of leukemia cells at leukemia fractions (LFs) of ∼10-11 (as the lower detection limit). The stability of the DPV signals obtained by oxidation of the extracted guanine on the rGONWs was studied after 20 cycles. Without the guanine extraction, the DPV peaks...
Chaos control in virtual cathode oscillator by cathode structural optimization
, Article Progress in Electromagnetics Research Symposium ; Volume 2015-January , 2015 , Pages 2225-2229 ; 15599450 (ISSN) ; 9781934142301 (ISBN) ; Pirmoradi, A ; Zabeh, E ; Sharif University of Technology
Electromagnetics Academy
2015
Abstract
In this paper, Virtual Cathode Oscillator as a microwave generator is studied concentrating on the nonlinear behavior of the microwave-plasma interaction that introduces chaos to the output voltage and power of the generator. It is shown that periodic oscillations of the electron beam strictly depend on the two most critical characteristics of the VCO, the input maximum voltage and the cathode radius. The chaos caused by the critical values of these two parameters, could restrict the maximum possible values of the input parameters, reducing the overall maximum output values. The effects of these two parameters are studied trough PIC-code simulations. The simulation results were used to...
Work hardening of Duratherm 600 cobalt superalloy using repetitive corrugation and straightening process
, Article Russian Journal of Non-Ferrous Metals ; Volume 51, Issue 1 , February , 2010 , Pages 59-61 ; 10678212 (ISSN) ; Paimozd, E ; Hashemi, S. M ; Sharif University of Technology
2010
Abstract
In this paper, the effect of repetitive corrugation and straightening (RCS) process on hardness of Duratherm 600 superalloy has been investigated. To do so, the RCS was carried out until 25 cycles using multiple teeth corrugative setup that the rotation of sample with 90° between cycles was utilized. The results show that the increasing of cycle number enhances the value of hardness. Also, the microstructures of samples are an evidence of slipbands formation during RCS showing the applied strain on the material. As a result, the increasing of hardness can be attributed to formation of subgrains, LAGBs and hcp martensitic plates at large strains
Toward chemical perfection of graphene-based gene carrier via ugi multicomponent assembly process
, Article Biomacromolecules ; Volume 17, Issue 9 , 2016 , Pages 2963-2971 ; 15257797 (ISSN) ; Akhavan, O ; Hashemi, E ; Shamsara, M ; Sharif University of Technology
American Chemical Society
2016
Abstract
The graphene-based materials with unique, versatile, and tunable properties have brought new opportunities for the leading edge of advanced nanobiotechnology. In this regard, the use of graphene in gene delivery applications is still at early stages. In this study, we successfully designed a new complex of carboxylated-graphene (G-COOH) with ethidium bromide (EtBr) and used it as a nanovector for efficient gene delivery into the AGS cells. G-COOH, with carboxyl functions on its surface, in the presence of EtBr, formaldehyde, and cyclohexylisocyanide were participated in Ugi four component reaction to fabricate a stable amphiphilic graphene-EtBr (AG-EtBr) composite. The coupling reaction was...
Ugi four-component assembly process: An efficient approach for one-pot multifunctionalization of nanographene oxide in water and its application in lipase immobilization
, Article Chemistry of Materials ; Volume 28, Issue 9 , 2016 , Pages 3004-3016 ; 08974756 (ISSN) ; Akhavan, O ; Hashemi, E ; Shamsara, M ; Sharif University of Technology
American Chemical Society
2016
Abstract
Graphene-based materials are revealing the leading edge of advanced technology for their exceptional physical and chemical properties. Chemical manipulation on graphene surface to tailor its unique properties and modify atomic structures is being actively pursued. Therefore, the discovery of robust and general protocols to anchor active functionality on graphene basal plane is still of great interest. Multicomponent reactions promise an enormous level of interest due to addressing both diversity and complexity in combinatorial synthesis, in which more than two starting compounds react to form a product derived from entire inputs. In this article, we present the first covalent...
Buckling of cracked cylindrical shells with internal pressure subjected to an axial load
, Article 2002 ASME Presures Vessels and Piping Conference, New Orleans, LA, 17 November 2002 through 22 November 2002 ; Volume 451 , 2002 , Pages 73-80 ; 0277027X (ISSN) ; Estekanchi, H. E ; Nayeb Hashemi, H ; Sharif University of Technology
2002
Abstract
Cylindrical shells constitute the main structural component in pressure vessels and pipelines. Buckling is one of the main failure considerations when designing these cylindrical shells. Defects such as cracks may develop during manufacturing or service life of these structures. These defects can severely affect their buckling behavior due to high stress field generated around these defects. Finite Element Analyses are performed to study the buckling behavior of cylindrical shells with and without a crack, under various internal pressures. Effects of crack length and its orientation on the buckling loads of cylindrical shells having a through or a thumbnail crack are studied. The results...
Dynamic response of cracked cylindrical shells with internal pressure
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings ; 2002 , Pages 257-265 ; 0791836282 (ISBN); 9780791836286 (ISBN) ; Nayeb Hashemi, H ; Estekanchi, H. E ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2002
Abstract
Sub-surface cracks in pipelines with internal pressure may severely affect their dynamic response. The extreme cases of these cracks are when these cracks go through the thickness of the pipes. Dynamic responses of cracked and un-cracked pipes with fixed ends and under various internal pressures were evaluated experimentally and theoretically. In the experimental part, the effects of pipe internal pressure on the resonant frequencies and damping of the pipe were evaluated. In the theoretical part, finite element analyses were performed to find dynamic response of pipes with various crack length and orientation respect to the axis of the pipe. The experimental results showed resonant...
Buckling of cracked cylindrical shells with internal pressure subjected to an axial load
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings ; 2002 , Pages 73-80 ; 0791836452 (ISBN); 9780791836453 (ISBN) ; Estekanchi, H. E ; Nayeb Hashemi, H ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2002
Abstract
Cylindrical shells constitute the main structural component in pressure vessels and pipelines. Buckling is one of the main failure considerations when designing these cylindrical shells. Defects such as cracks may develop during manufacturing or service life of these structures. These defects can severely affect their buckling behavior due to high stress field generated around these defects. Finite Element Analyses are performed to study the buckling behavior of cylindrical shells with and without a crack, under various internal pressures. Effects of crack length and its orientation on the buckling loads of cylindrical shells having a through or a thumbnail crack are studied. The results...
Graphene oxide for rapid determination of testosterone in the presence of cetyltrimethylammonium bromide in urine and blood plasma of athletes
, Article Materials Science and Engineering C ; Volume 61 , 2016 , Pages 246-250 ; 09284931 (ISSN) ; Akhavan, O ; Ghaderi, E ; Hashemi, E ; Mortazavi, S. S ; Farmany, A ; Sharif University of Technology
2016
Abstract
Electro-reduction behavior of testosterone at reduced graphene oxide/glassy carbon electrode (rGO/GCE) was studied. Cationic surfactant cetyltrimethylammonium bromide (CTAB) enhanced the reduction peak of testosterone. In borate buffer (pH 5.4) CTAB-testosterone showed a reduction peak at - 1.1 V (versus, Ag/AgCl). The increment of peak current obtained by deducting the reduction peak current of the CTAB-testosterone was rectilinear with testosterone concentration in the range of 2.0 to 210.0 nM, with a detection limit of 0.1 nM. The sensor was used for quantification of testosterone in biological fluids and drug
The impact of pavement permeability on time of concentration in a small urban watershed with a semi-arid climate
, Article Water Resources Management ; Volume 34, Issue 9 , 2020 , Pages 2969-2988 ; Tajrishy, M ; Jalilvand, E ; Sharif University of Technology
Springer
2020
Abstract
Despite the popularity of the permeable pavements in urban areas in recent years, a few empirical equations have been developed to estimate the time of concentration (Tc) on pervious surfaces, and almost none of them is evaluated over the permeable pavements. In this paper, we aim to investigate the effect of low impact development (LID) on Tc and develop a new equation for estimating overland flow Tc compatible with both permeable and impermeable pavements in small urban watersheds with a semi-arid climate. An experimental model was devised to determine the new equation. Synthetic rainfall (22–40 mm.h−1) was applied to a rectangular shaped (6 m × 1 m) test watershed with an adjustable...
Buckling of the composite cracked cylindrical shells subjected to axial load
, Article 2003 ASME International Mechanical Engineering Congress, Washington, DC, 15 November 2003 through 21 November 2003 ; Volume 470 , 2003 , Pages 87-93 ; 0277027X (ISSN) ; Nayeb Hashemi, H ; Estekanchi, H. E ; ASME ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2003
Abstract
Cylindrical shells constitute the main structural components in pressure vessels and pipelines. Cylindrical shells made of fiber-reinforced composites are now being considered in the design of many components due to their high specific strength and stiffness. Buckling is one of the main failure considerations, when designing the cylindrical shells. The buckling behavior of the composite cylindrical shells can severely be compromised by introducing defect in the structure, due to high stress field generated around these defects. Defects could be generated during service due to cyclic loading or during manufacturing. A reliable operation of these structures require to understand the effects of...
Graphene as a flexible electrode: Review of fabrication approaches
, Article Journal of Materials Chemistry A ; Volume 5, Issue 34 , 2017 , Pages 17777-17803 ; 20507488 (ISSN) ; Reeves, S. P ; Hashemi, N ; Thomas, D. G ; Kavak, E ; Montazami, R ; Hashemi, N. N ; Sharif University of Technology
Royal Society of Chemistry
2017
Abstract
In recent years, the technological advancement of supercapacitors has been increasing exponentially due to the high demand in electronic consumer products. As so, researchers have found a way to meet that demand by fabricating graphene. As developments are made toward the future, two big advancements to be made are large-scale fabrication of graphene and fabricating graphene as a flexible electrode. This would allow for use in larger products and for manipulation of the unique properties of graphene to accommodate superior design alternatives. While large scale production is still mentioned, this review is specifically focusing on different methods used to fabricate graphene as a flexible...
Fully fuzzified linear programming, solution and duality
, Article Journal of Intelligent and Fuzzy Systems ; Volume 17, Issue 3 , 2006 , Pages 253-261 ; 10641246 (ISSN) ; Modarres, M ; Nasrabadi, E ; Nasrabadi, M. M ; Sharif University of Technology
2006
Abstract
In this paper, we propose a two-phase approach to find the optimal solutions of a class of fuzzy linear programming problems called fully fuzzified linear programming (FFLP), where all decision parameters and variables are fuzzy numbers. Our approach is constructed on the basis of comparison of mean and standard deviation of fuzzy numbers. In this approach, the first phase maximizes the possibilistic mean value of fuzzy objective function and obtains a set of feasible solutions. The second phase minimizes the standard deviation of the original fuzzy objective function, by considering all basic feasible solutions obtained at the end of the first phase. The advantage of the proposed approach...
An analytical approach in prediction of necking and suitable load path in tube hydroforming by using the strain gradient
, Article SAE Technical Papers, 20 April 2009 through 20 April 2009, Detroit, MI ; 2009 ; Masoumi, E ; Safikhani, A. R ; Hashemi, R ; Abrinia, K ; Sharif University of Technology
2009
Abstract
A theoretical forming limit stress diagram (FLSD) for necking prediction which is based on the strain gradient theory of plasticity in conjunction with the M-K approach was represented and used in tube hydroforming. This approach introduces an internal length scale into conventional constitutive equations and takes into account the effects of deformation inhomogeneity and material softening. The nonlinear second order ordinary differential equation of the thickness of tube has been solved by collocation method. It has been shown that this method overcomes the imperfection sensitivity encountered in the conventional M-K method. The predicted FLSD has been compared with published experimental...
Sol-gel synthesis of Mn1.5Co1.5O4 spinel nano powders for coating applications
, Article Materials Research Bulletin ; Volume 102 , 2018 , Pages 180-185 ; 00255408 (ISSN) ; Dayaghi, A. M ; Askari, M ; Gannon, P. E ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Mn1.5Co1.5O4 oxide spinels are widely used as protective coatings for stainless steel interconnects within planar solid oxide fuel cell stacks. Containing both cubic and tetragonal crystalline phases, these Mn/Co oxide spinels exhibit favorable thermal stability and electronic conductivity for the SOFC interconnect application. Slurry-based coating applications of Mn/Co oxides require precursor powders, which can benefit from being nano-structured. In this study, the sol-gel synthesis of nanocrystalline Mn1.5Co1.5O4 spinel is investigated. The decomposition of sol-gel precursors, as well as the crystalline phase structures and microstructures of the product Mn1.5Co1.5O4 are characterized by...
Synthesis of dithiocarbamates by Markovnikov addition reaction in PEG and their application in amidoalkylation of naphthols and indoles
, Article Journal of the Brazilian Chemical Society ; Volume 26, Issue 7 , 2015 , Pages 1500-1508 ; 01035053 (ISSN) ; Dadras, A ; Ramezani, M ; Shamiri, E. V ; Hooshmand, S. E ; Hashemi, M. M ; Sharif University of Technology
Sociedade Brasileira de Quimica
2015
Abstract
Synthesis of dithiocarbamates by the one-pot three-component Markovnikov addition reaction of an amine, carbon disulfide and an alkyl vinyl ether or N-vinylpyrrolidone is reported in polyethylene glycol (PEG) under a mild and green procedure with high yields and completely regiospecific. Also, the products were used as efficient starting materials for amidoalkylation of electron-rich arenes such as naphthols and indoles
Exergy analysis and optimization of natural gas liquids recovery unit
, Article International Journal of Air-Conditioning and Refrigeration ; Volume 29, Issue 1 , 2021 ; 20101325 (ISSN) ; Norouzi, N ; Shiva, N ; Mahmoodi Folourdi, R ; Hashemi Bahremani, E ; Sharif University of Technology
World Scientific
2021
Abstract
The Natural Gas Liquids (NGL) recovery unit is one of the processes that requires cooling. The sweetened gas enters this unit after the dehydration stage, and the final product called NGL Product is stored and ready for consumption or export. In this research, the first, one of the NGL units, is simulated with HYSYS software. Three types of processes with different cooling systems are studied using the exergy analysis method. Joule-Thomson's combination with the expander is selected for its high exergy efficiency, and the exergy efficiency function has been selected as the objective function 1 to optimize this process mathematically based on this study's findings. The critical term in this...
Cognitive MIMO radars: An information theoretic constrained code design method
, Article European Signal Processing Conference, 28 August 2016 through 2 September 2016 ; Volume 2016-November , 2016 , Pages 2215-2219 ; 22195491 (ISSN) ; 9780992862657 (ISBN) ; Haj Mirza Alian, E ; Modarres Hashemi, M ; Nayebi, M. M ; Sharif University of Technology
European Signal Processing Conference, EUSIPCO
2016
Abstract
A novel information theoretic code design approach for cognitive multiple-input multiple-output (MIMO) radars is proposed in the current paper. In the suggested solution, we consider an agile multi-antenna radar with spectral cognition and design optimized transmission codes considering practical limitations such as peak-to-average power ratio (PAR) and spectral coexistence in a spectrally crowded environment. As exact performance expressions for the detector is not analytically tractable in this case, an information theoretic approach is taken into account to design the transmission codes. Simulation results illustrate the efficiency of the proposed method