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Modeling and Forecasting of Carbon Dioxide Concentration over the Australian Daintree Rainforest
, M.Sc. Thesis Sharif University of Technology ; Moghim, Sanaz (Supervisor)
Abstract
In recent decades, the concentration of carbon dioxide in the atmosphere has increased. Carbon dioxide is a greenhouse gas that raises the Earth’s temperature, and it can endanger life on Earth. This study uses the 6.2 version of the Regional Atmospheric Modeling System (RAMS) with its simple biosphere model (SiB-2) to simulate and forecast the concentration of carbon dioxide over the Daintree rainforest in Australia. This analysis helps to better understand the interaction between the biosphere and the atmosphere. Results of the carbon dioxide simulation were compared and validated with the observed values of the satellite product (MultiInstrumentFusedXCO2). Based on effective parameters,...
Properties of a hierarchical network based on the star graph
, Article Information Sciences ; Vol. 180, issue. 14 , 2010 , p. 2802-2813 ; ISSN: 00200255 ; Sarbazi-Azad, H ; Sharif University of Technology
2010
Abstract
This paper introduces a new class of interconnection networks named star-pyramid. An n-level star-pyramid is formed by piling up star graphs of dimensions 1 to n in a hierarchy, connecting any node in each i-dimensional star, 1 < i ? n, to a node in the (i - 1)-dimensional star whose index is reached by removing the i symbol from the index of the former node in the i-dimensional star graph. Having extracted the properties of the new topology, featuring topological properties, a minimal routing algorithm, a simple but efficient broadcast algorithm, Hamiltonicity and pancyclicity, we then compare the network properties of the proposed topology and the well-known pyramid topology. We show that...
Properties of a hierarchical network based on the star graph
, Article Information Sciences ; Volume 180, Issue 14 , July , 2010 , Pages 2802-2813 ; 00200255 (ISSN) ; Sarbazi Azad, H ; Sharif University of Technology
2010
Abstract
This paper introduces a new class of interconnection networks named star-pyramid. An n-level star-pyramid is formed by piling up star graphs of dimensions 1 to n in a hierarchy, connecting any node in each i-dimensional star, 1 < i ≤ n, to a node in the (i - 1)-dimensional star whose index is reached by removing the i symbol from the index of the former node in the i-dimensional star graph. Having extracted the properties of the new topology, featuring topological properties, a minimal routing algorithm, a simple but efficient broadcast algorithm, Hamiltonicity and pancyclicity, we then compare the network properties of the proposed topology and the well-known pyramid topology. We show that...
Interference modeling and generalized static capacity for uplink CDMA cellular networks
, Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 17-22 ; 1424410940 (ISBN); 9781424410941 (ISBN) ; Ashtiani, F ; Sharif University of Technology
2007
Abstract
In this paper, we propose a new approach in computing interference distribution and outage probability for uplink CDMA cellular networks. In this approach, we model time-varying interference as a discrete-time Markov chain with flexible approximation and find its steady state distribution. Our approach is based on tracing the time variation of the effective factors in interference such as spatial locations, activity status, and shadowing status for the connected users. To this end, we approximate shadowing with several discrete levels by Lloyd algorithm. Moreover, we incorporate correlation properties of the shadowing status in our model. Then, we map the effective factors onto the...
A two-stage pipelined passive charge-sharing SAR ADC
, Article APCCAS 2008 - 2008 IEEE Asia Pacific Conference on Circuits and Systems, Macao, 30 November 2008 through 3 December 2008 ; January , 2008 , Pages 141-144 ; 9781424423422 (ISBN) ; Bakhtiar, M. S ; Sharif University of Technology
2008
Abstract
This paper presents a new ADC based on using passive charge sharing SAR ADC in a 2-stage pipeline architecture. The charge domain operation of passive charge sharing ADC poses an inherent limitation on its resolution. The proposed architecture increases the achievable resolution with a low power overhead. Designed and simulated in a 0.18um CMOS process, the 12-bits, 40MS/sec ADC core consumes 7mW from a 1.8V supply
The star-pyramid graph: An attractive alternative to the pyramid
, Article 10th Asia-Pacific Conference on Advances in Computer Systems Architecture, ACSAC 2005, Singapore, 24 October 2005 through 26 October 2005 ; Volume 3740 LNCS , 2005 , Pages 509-519 ; 03029743 (ISSN); 3540296433 (ISBN); 9783540296430 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
2005
Abstract
This paper introduces a new class of interconnection networks named Star-Pyramid, SP(n). A star-pyramid of dimension n is formed by piling up star graphs of dimensions 1 to n in a hierarchy, connecting any node in each i-dimensional star, 1< i ≤ n, to a node in (i - 1)-star whose index is reached by removing the i symbol from the index of the former node in the i-star graph. Having extracted the properties of the new topology, featuring topological properties, a simple routing algorithm and Hamiltonicity then we compare the network properties of the proposed topology and the well-known pyramid topology. We show that the star-pyramid is more fault-tolerant and has less network diameter than...
Comparing half-metallic, MOKE, and thermoelectric behavior of the CrTiZ (Z = As, P) half-Heuslers: A DFT study
, Article Materials Research Express ; Volume 8, Issue 4 , 2021 ; 20531591 (ISSN) ; Zelati, A ; Boochani, A ; Arman, A ; Mirzaei, S ; Sharif University of Technology
IOP Publishing Ltd
2021
Abstract
Structural, half-metallic, magneto-optic, and thermoelectric properties of CrTiZ (Z = As, P) half-Heusleres compounds are investigated based on density functional theory. These compounds have mechanical stability in the ferromagnetic state with a high bulk modulus. They are often half-metallic with a large and integer magnetic moment and are very attractive in spintronics, magneto-optics applications. The magnetic moments of CrTiAs and CrTiP were 2.9865 μB and 3.00 μB, respectively, which were attributed to their ferromagnetic phase. Additionally, the positive sign of the phonon branches indicates the dynamic stability of these compounds. Applying both GGA and mBJ approximations, CrTiAs and...
The Effect of Rudder Angle on Ship’s Fuel Consumption
, M.Sc. Thesis Sharif University of Technology ; Khorasanchi, Mahdi (Supervisor) ; Zare, Arman (Co-Supervisor)
Abstract
The aim of this research is to investigate the effect of speed and direction of current on ship fuel consumption. A KCS benchmark model has been numerically studied in calm water and fourteen current and wind conditions with the same speed and different directions to determine how the ship performance is dependent on flow conditions. The model has been simulated in an artificial basin propelled by a single right-handed propeller via a CFD commercial code. Numerical results revealed a linear relationship between the deviation of current and wind from head-sea or following-sea conditions and the rudder angle. The head-sea and following-sea currents and winds increased and decreased the lateral...
Generalized Growth Models
, M.Sc. Thesis Sharif University of Technology ; Moghimi-Araghi, Saman (Supervisor)
Abstract
Edwards-Wilkinson’s equation can be achieved from a Hamiltonian. When we have the Hamiltonian for the system, there are common approaches that makes it out of critical. In other words,the ”mass” should be added to the system. In this study we have tried to simulate and solve analytically these models that are involved mass term. We try to onstruct these mass terms in a way that have a minimum impact on the system and we study the quantities that characterize the out of critical behaviors
A Temperature Dependant Multiscale Modeling of Crack Growth in Nano Materials
, M.Sc. Thesis Sharif University of Technology ; Khoei, Amir Reza (Supervisor)
Abstract
The fact that materials and crack behave differently under different temperatures, brings a need for further investigation in this field. Recent studies regarding this behavior are mainly based on molecular dynamic method. While this method garuntee a highpercicion, the computational costs of this method can be high when dealing with crack propagation problem. Taking advantage of multiscale methods allows us to overcome this challenge by reducing the calculation time while providing acceptable results. In this research a multi-scale method capable of considering thermal effects has been developed. A concurrent model is created by using theory of elasticity for continuum part and taking...
Recent advances in surface engineering of superparamagnetic iron oxide nanoparticles for biomedical applications
, Article Journal of the Iranian Chemical Society ; Volume 7, Issue SUPPL. 1 , 2010 , Pages S1-S27 ; 1735207X (ISSN) ; Simchi, A ; Imani, M ; Sharif University of Technology
2010
Abstract
Superparamagnetic iron oxide nanoparticles (SPIONs) are promising materials for various biomedical applications including targeted drug delivery and imaging, hyperthermia, magneto-transfections, gene therapy, stem cell tracking, molecular/cellular tracking, magnetic separation technologies (e.g. rapid DNA sequencing), and detection of liver and lymph node metastases. The most recent applications for SPIONs for early detection of inflammatory, cancer, diabetes and atherosclerosis have also increased their popularity in academia. In order to increase the efficacy of SPIONs in the desired applications, especial surface coating/characteristics are required. The aim of this article is to review...
Cytotoxicity of uncoated and polyvinyl alcohol coated superparamagnetic iron oxide nanoparticles
, Article Journal of Physical Chemistry C ; Volume 113, Issue 22 , 2009 , Pages 9573-9580 ; 19327447 (ISSN) ; Simchi, A ; Imani, M ; Sharif University of Technology
2009
Abstract
Superparamagnetic iron oxide nanoparticles (SPION) are being increasingly used in various biomedical applications such as hyperthermia, cell and protein separation, enhancing resolution of magnetic resonance imaging, and drug delivery. However, the toxicity data for SPION are limited. In this study, uncoated and single polyvinyl alcohol coated SPION with high chemical reactivity (due to the bigger surface area) were synthesized using a coprecipitation method. Cytotoxicity of these magnetic nanoparticles and their ability to cause arrest in cell life-cycles was investigated. Interaction of these nanoparticles with adhesive mouse fibroblast cell line (L929) was probed using MTT assay. High...
Size-controlled synthesis of superparamagnetic iron oxide nanoparticles and their surface coating by gold for biomedical applications [electronic resource]
, Article Journal of Magnetism and Magnetic Materials ; Volume 324, Issue 23, November 2012, Pages 3997–4005 ; Simchi, A ; Imani, M ; Costa, B.F.O ; Sharif University of Technology
Abstract
The size mono-dispersity, saturation magnetization, and surface chemistry of magnetic nanoparticles (NPs) are recognized as critical factors for efficient biomedical applications. Here, we performed modified water-in-oil inverse nano-emulsion procedure for preparation of stable colloidal superparamagnetic iron oxide NPs (SPIONs) with high saturation magnetization. To achieve mono-dispersed SPIONs, optimization process was probed on several important factors including molar ratio of iron salts [Fe3+ and Fe2+], the
Evaluation of the topographical surface changes of silicon wafers after annealing and plasma cleaning
, Article Silicon ; Volume 12, Issue 11 , 2020 , Pages 2563-2570 ; Ţălu, Ş ; Dallaev, R ; Arman, A ; Sobola, D ; Salerno, M ; Sharif University of Technology
Springer Science+Business Media B.V
2020
Abstract
Purpose: The morphological stability of silicon single crystal wafers was investigated, after performing cleaning surface treatments based on moderate temperature annealing and plasma sputtering. Methods: The wafer surfaces were measured by Tapping mode atomic force microscopy in air, before and after the different treatments. The 3D images were segmented by watershed algorithm identifying the local peaks, and the stereometric parameters were extracted thereof. The analysis of variance allowed to better assess the statistically significant differences. Results: All the resulting quantities were critically discussed. It appeared that the different cleaning treatments affected differently the...
Investigation of the Damage Imposed on Steel Structures under Near Field Earthquakes from a Performance Based Design Viewpoint
, M.Sc. Thesis Sharif University of Technology ; Rahimzadeh Rofooei, Fayaz (Supervisor)
Abstract
The considerable structural damage caused by near field earthquakes has revealed the need for further research on their characteristics and their corresponding effects on structures. The short-duration, high- energy pulses present in these types of earthquakes impose high demands on the structures compared to far field ground motions. Thus, more research is needed to improve the current design methods, especially from a performance based point of view for the structures close to faults. This study is about damage assessment of steel moment resisting frame structures under near-field ground motions from a performance based design point of view. A number of 3 and 9-story, 3-D structural model...
Resource placement in Cartesian product of networks
, Article Journal of Parallel and Distributed Computing ; Vol. 70, issue. 5 , May , 2010 , p. 481-495 ; ISSN: 7437315 ; Sarbazi-Azad, H ; Zomaya, A.Y ; Sharif University of Technology
2010
Abstract
The utilization of the limited resources of a multiprocessor or multicomputer system is a primary performance issue which is crucial for the design of many scheduling algorithms. While many of the existing parallel machines benefit from a regular product network topology, almost none of the previous resource placement techniques have come to recognize and exploit this inherent regularity. This paper introduces several novel algorithms for deriving resource placement schemes in product networks based on the assumption of perfect resource placement in their underling basic graphs. Our techniques use known schemes for the basic networks as their building blocks for deploying the resource...
Recent advances in surface engineering of superparamagnetic iron oxide nanoparticles for biomedical applications
, Article Journal of the Iranian Chemical Society ; Volume 7, Issue 2 , July , 2010 , pp. S1-S27 ; 1735-2428 ; Simchi, A. (Abdolreza) ; Imani, M ; Sharif University of Technology
2010
Abstract
Superparamagnetic iron oxide nanoparticles (SPIONs) are promising materials for various biomedical applications including targeted drug delivery and imaging, hyperthermia, magneto-transfections, gene therapy, stem cell tracking, molecular/cellular tracking, magnetic separation technologies (e.g. rapid DNA sequencing), and detection of liver and lymph node metastases. The most recent applications for SPIONs for early detection of inflammatory, cancer, diabetes and atherosclerosis have also increased their popularity in academia. In order to increase the efficacy of SPIONs in the desired applications, especial surface coating/characteristics are required. The aim of this article is to review...
H2S gasochromic effect of mixed ammonium salts of phosphomolybdate nanoparticles synthesized by microwave assisted technique
, Article Sensors and Actuators, B: Chemical ; Volume 237 , 2016 , Pages 715-723 ; 09254005 (ISSN) ; Iraji zad, A ; Tadjarodi, A ; Sharif University of Technology
Elsevier B.V
2016
Abstract
In the present paper, new H2S gasochromic nanomaterial of mixed silver nickel ammonium phosphomolybdate synthesized by microwave assisted technique is reported. The microwave treatment was performed in the solid phase using urea and ammonium nitrate as the promoter and oxidizer agents. The designed process allows rapid synthesis of large amounts of this product in nanosized particulate morphology. Morphological and structural features of the prepared products were studied in detail. Chemical analyses indicated a stoichiometry of (NH4)0.5Ni0.75AgPMo12O40·4H2O revealing a Keggin-type framework with substitution of silver and nickel cations in its secondary structure. A home-made set-up was...
Mixed ammonium silver phosphomolybdate salt nanostructures; solid state synthesis, characterization of driving agent role and photocatalytic property
, Article Materials Letters ; Volume 161 , December , 2015 , Pages 464-467 ; 0167577X (ISSN) ; Iraji Zad, A ; Imani, M ; Sharif University of Technology
Elsevier
2015
Abstract
A green mechanochemical technique has been developed for the synthesis of mixed ammonium silver phosphomolybdate salt, (NH4 )1.6 Ag1.4 PMo12 O40 .4H2 O with sheet-like nanostructure. The reaction was prompted using acetamide/NH4 NO3 at room temperature. The change of driving agent to urea at the same conditions led to an epitaxial growth of hierarchical microstructure of this polyoxoanion. The morphological and structural features of the prepared specimens were discussed in detail. The photocatalytic performance of the resulting nanosheets for removing 4-nitrophenol (4-NP) in water under visible light...
Resource placement in Cartesian product of networks
, Article Journal of Parallel and Distributed Computing ; Volume 70, Issue 5 , 2010 , Pages 481-495 ; 07437315 (ISSN) ; Sarbazi-Azad, H ; Zomaya, A.Y ; Sharif University of Technology
2010
Abstract
The utilization of the limited resources of a multiprocessor or multicomputer system is a primary performance issue which is crucial for the design of many scheduling algorithms. While many of the existing parallel machines benefit from a regular product network topology, almost none of the previous resource placement techniques have come to recognize and exploit this inherent regularity. This paper introduces several novel algorithms for deriving resource placement schemes in product networks based on the assumption of perfect resource placement in their underling basic graphs. Our techniques use known schemes for the basic networks as their building blocks for deploying the resource...