Search for: calculation
Total 377 records
2D analysis of the effects of geometry on the response of high-T c superconductive bolometric detectors, Article IEEE Transactions on Applied Superconductivity ; Volume 19, Issue 3 , 2009 , Pages 484-488 ; 10518223 (ISSN) ; Kokabi, A. R ; Pourhashemi, A ; Moftakharzadeh, A ; Khorasani, S ; Banzet, M ; Schubert, J ; Sharif University of Technology
We present a new approach for analytical modeling and calculating the response of high-Tc superconductive transition edge sensors in a wide range of modulation frequencies for different configurations of the film patterns. The method used here is based on solving the heat transfer differential equation for two different time varying heat sources, which are related to the absorbed radiated power. The used method employs two-dimensional boundary conditions for describing meander-line patterned devices. The results from the applied method are in better agreement with those obtained from the frequency response measurements of the characterized samples, than the previously developed models. In...
Neutron spectroscopy with soft computing: Development of a computational code based on Support Vector Machine (SVM) for reconstruction of neutron energy spectrum, Article Journal of Instrumentation ; Volume 14, Issue 2 , 2019 ; 17480221 (ISSN) ; Sharif University of Technology
Institute of Physics Publishing 2019
This paper presents a developed computational code based on Support Vector Machine (SVM) for reconstruction of energy spectrum of neutron source. To reconstruct unknown energy spectrum using known neutron pulse height distribution, the developed machine is trained by known neutron pulse height distribution of detector and corresponding energy spectrum of neutron source. Validation and testing are the next steps to verify the validity of the calculations done with the developed computational code. The calculated neutron pulse height distributions due to randomly generated energy spectrum using MCNPX-ESUT (MCNPX-Energy engineering of Sharif University of Technology) computational code are used...
Article Bioresource Technology ; Volume 99, Issue 5 , 2008 , Pages 1118-1124 ; 09608524 (ISSN) ; Sharbatmaleki, M ; Pourrezaie, P ; Borghei, G ; Sharif University of Technology
The process kinetics of a lab-scale upflow aerobic immobilized biomass (UAIB) reactor using simulated sugar-manufacturing wastewater as feed was investigated. The experimental unit consisted of a 22 l reactor filled with high porosity pumice stone. The UAIB reactor was tested under different organic loads and different hydraulic retention times (HRT) and the substrate loading removal rate was compared with prediction of Stover-Kincannon model, second-order model and the first order substrate removal model. After obtaining steady-state conditions, organic loading rate was increased from 750 to 4500 g COD/m3 day to resemble wastewater from sugar production lines, and hydraulic retention time...
Article IEEE Transactions on Energy Conversion ; Volume 35, Issue 4 , 2020 , Pages 1727-1735 ; Tahami, F ; Capolino, G. A ; Vaschetto, S ; Nasiri Gheidari, Z ; Henao, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2020
The fault-tolerant capability is a prerequisite for electrical safety-critical applications. In this regard, multi-phase induction motors are well-known actuators used to provide this feature. Compared to conventional three-phase machines with distributed windings, induction machines having concentrated windings could be more fault-tolerant because of increasing the number of phases. In addition, concentrated windings have shorter end-winding and less required copper weight which makes it a lower cost solution compared to distributed windings. However, concentrated windings adversely increase the distortion of the air gap flux density which affects motor performances. In this paper, a...
Automated trace determination of earthy-musty odorous compounds in water samples by on-line purge-and-trap-gas chromatography-mass spectrometry, Article Journal of Chromatography A ; Volume 1136, Issue 2 , 2006 , Pages 170-175 ; 00219673 (ISSN) ; Lacorte, S ; Bagheri, H ; Barceló, D ; Sharif University of Technology
An automated technique based on purge-and-trap coupled to gas chromatography with mass spectrometric detection has been developed and optimized for the trace determination of five of the most important water odorants; 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, 2-methylisoborneol, 2,4,6-trichloroanisole and geosmin. The extraction method was absolutely solvent-free. Analytes were purged from 20 ml of water sample containing sodium chloride at room temperature by a flow of He and trapped on a Tenax sorbent. The desorption step was performed with helium and temperature programming and desorbed analytes were directly transferred to a gas chromatograph coupled to a mass...
Comparative evaluation of six quantitative lifting tools to estimate spine loads during static activities, Article Applied Ergonomics ; Volume 48 , 2015 , Pages 22-32 ; 00036870 (ISSN) ; Arjmand, N ; Shirazi Adl, A ; Plamondon, A ; Schmidt, H ; Sharif University of Technology
Elsevier Ltd 2015
Different lifting analysis tools are commonly used to assess spinal loads and risk of injury. Distinct musculoskeletal models with various degrees of accuracy are employed in these tools affecting thus their relative accuracy in practical applications. The present study aims to compare predictions of six tools (HCBCF, LSBM, 3DSSPP, AnyBody, simple polynomial, and regression models) for the L4-L5 and L5-S1 compression and shear loads in twenty-six static activities with and without hand load. Significantly different spinal loads but relatively similar patterns for the compression (R2>0.87) were computed. Regression models and AnyBody predicted intradiscal pressures in closer agreement with...
Thermodynamic modeling for hydrogen production from biomass and evaluation of biomass energy technologies, Article Biotechniques for Air Pollution Control - Proceedings of the 3rd International Congress on Biotechniques for Air Pollution Control, 28 September 2009 through 30 September 2009, Delft ; 2010 , Pages 269-273 ; 9780415582704 (ISBN) ; Saboohi, Y ; Hashemi, N ; Vossoughi, M ; Pazuki, G. R ; Sharif University of Technology
Compared with fossil fuel, biomass is a clean energy with zero CO 2 emission, because CO 2 is fixed by photosynthesis during biomass growth and released again during utilization. Due to its low energy density, direct use of biomass is not convenient. Thus, it is necessary to convert biomass to fuel gas, such as hydrogen, which can be used cleanly and highly efficiently in fuel cell. Thermo-chemical gasification is likely to be the most cost-effective conversion process and it is promising technology for renewable hydrogen production by utilizing biomass. Biomass gasification produces a mixture of gases (mainly consisting of H 2, CO, CO 2, CH 4 and higher hydrocarbons), solids (char) and...
Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 75, Issue 3 , 2010 , Pages 970-977 ; 13861425 (ISSN) ; Najafpour, M. M ; Boghaei, D. M ; Sharif University of Technology
Charge-transfer (CT) complexes formed from the reactions of 4-nitropyrocatechol (4-nCat) as an electron acceptor with four amino alcohols: 2-aminoethanol, 1-amino-2-propanol, 4-aminobutanol and N-(2-hydroxyethyl)-1,3-diaminopropane (NHEDAP) as electron donors, have been studied spectrophotometrically in H2O and H2O/EtOH at 20, 25, 30, 35 and 40 °C. The calculated values of the oscillator strength and transition moment confirm the formation of CT-complexes. The thermodynamic and spectroscopic parameters were also evaluated for the formation of CT-complexes. The equilibrium constants ranged from 9.00 to 2.20 l mol-1 (M-1). These interactions are exothermic and have relatively large standard...
DFT study of the interaction of cytidine and 2′-deoxycytidine with Li+, Na+, and K+: effects of metal cationization on sugar puckering and stability of the N-glycosidic bond, Article Carbohydrate Research ; Volume 344, Issue 6 , 2009 , Pages 771-778 ; 00086215 (ISSN) ; Fattahi, A. R ; Pourjavadi, A ; Sharif University of Technology
Density functional theory (DFT) calculations were performed at the B3LYP level with a 6-311++G(d,p) basis set to systematically explore the geometrical multiplicity and binding strength for complexes formed by Li+, Na+, and K+ with cytidine and 2′-deoxycytidine. All computational studies indicate that the metal ion affinity (MIA) decreases from Li+ to Na+ and K+ for cytosine nucleosides. For example, for cytidine the affinity for the above metal ions are 79.5, 55.2, and 41.8 and for 2′-deoxycytidine, 82.8, 57.4, and 42.2 kcal/mol, respectively. It is also interesting to mention that linear correlations between calculated MIA values and the atomic numbers (Z) of the above metal ions were...
A state-of-the-art model for spatial and stochastic oil spill risk assessment: A case study of oil spill from a shipwreck, Article Environment International ; Volume 126 , 2019 , Pages 309-320 ; 01604120 (ISSN) ; Arneborg, L ; Lindgren, J. F ; Lindhe, A ; Rosén, L ; Raie, M ; Axell, L ; Hassellöv, I. M ; Sharif University of Technology
Elsevier Ltd 2019
Oil spills are serious environmental issues that potentially can cause adverse effects on marine ecosystems. In some marine areas, like the Baltic Sea, there is a large number of wrecks from the first half of the 20th century, and recent monitoring and field work have revealed release of oil from some of these wrecks. The risk posed by a wreck is governed by its condition, hazardous substances contained in the wreck and the state of the surrounding environment. Therefore, there is a need for a common standard method for estimating the risks associated with different wrecks. In this work a state-of-the-art model is presented for spatial and stochastic risk assessment of oil spills from...
Quantitative structure - Mobility relationship study of a diverse set of organic acids using classification and regression trees and adaptive neuro-fuzzy inference systems, Article Electrophoresis ; Volume 29, Issue 2 , 2008 , Pages 363-374 ; 01730835 (ISSN) ; Shahbazikhah, P ; Sharif University of Technology
A quantitative structure-mobility relationship was developed to accurately predict the electrophoretic mobility of organic acids. The absolute electrophoretic mobilities (μ0) of a diverse dataset consisting of 115 carboxylic and sulfonic acids were investigated. A set of 1195 zero- to three-dimensional descriptors representing various structural characteristics was calculated for each molecule in the dataset. Classification and regression trees were successfully used as a descriptor selection method. Four descriptors were selected and used as inputs for adaptive neuro-fuzzy inference system. The root mean square errors for the calibration and prediction sets are 1.61 and 2.27, respectively,...
Two-dimensional quantum simulation of scaling effects in ultrathin body MOSFET structure: NEGF approach, Article 14th International Workshop on the Physics of Semiconductor Devices, IWPSD, Mumbai, 16 December 2007 through 20 December 2007 ; 2007 , Pages 240-242 ; 9781424417285 (ISBN) ; Dehdashti, N ; Faez, R ; Sharif University of Technology
For the first time, we present self-consistent solution of ultrathin body device structures to investigate the device parameters variation on the characteristics of nanoscale MOSFET. Our two dimensional (2-D) device simulator Is based on Nonequlibrium Green's Function (NEGF) forma lism. Starting from a basic structure (DG-MOSFET) with a gate length of 10 nm, variation of gate length, channel thickness, gate oxide parameters was carried out in connection with the numerical calculation of device characteristics. In this work Quantum transport equations are solved in 2-D by NEGF method in active area of the device to obtain the charge density and Poisson's equation is solved in entire domain of...
Highly efficient of molybdenum trioxide-cadmium titanate nanocomposites for ultraviolet light photocatalytic and antimicrobial application: Influence of reactive oxygen species, Article Journal of Photochemistry and Photobiology B: Biology ; Volume 191 , 2019 , Pages 75-82 ; 10111344 (ISSN) ; Hosseini, M ; Fakhri, A ; Salari Rad, S ; Hadadi, T ; Nobakht, N ; Sharif University of Technology
Elsevier B.V 2019
In the present work we report the enhanced UV light photocatalytic performance of cadmium titanate photocatalyst by MoO 3 for Drug pollutant degradation. The nano photocatalyst sample was synthesized employing the Pechini-ultrasonic-hydrothermal route. Therefore, the nano photocatalyst were characterized by various analytical devices. The wide scan X-ray photoelectron spectral study confirmed the MoO 3 in the CdTiO 3 matrix. The crystallite size calculated with the Debye-Scherrer equation (55.4, 57.0, 61.2 and 63.1 nm for pure CdTiO 3 , MoCdTi-0, MoCdTi-1, and MoCdTi-2 nanocomposites, respectively). SEM micrographs revealed nanowire morphology indicated the crystalline nature of the sample....
Degradation of BTEX in groundwater by nano-CaO2 particles activated with L-cysteine chelated Fe(III): enhancing or inhibiting hydroxyl radical generation, Article Water Supply ; Volume 21, Issue 8 , 2021 , Pages 4429-4441 ; 16069749 (ISSN) ; Ali, M ; Cui, C ; Lyu, S ; Sharif University of Technology
IWA Publishing 2021
The simultaneous oxidation performance of benzene, toluene, ethylbenzene, and xylene (BTEX) by nanoscale calcium peroxide particles (nCaO2) activated with ferric ions (Fe(III)) and the mechanism of the enhancement of BTEX degradation by L-cysteine (L-cys) were investigated. The batch experimental results showed that the nCaO2/Fe(III)/L-cys process was effective in the destruction of BTEX in both ultrapure water and actual groundwater. A proper amount of L-cys could enhance BTEX degradation due to the promotion of Fe(II)/Fe(III) redox cycles by the participation of L-cys, but an excessive presence of L-cys would cause inhibition. Adding 1.0 mM L-cys to the nCaO2/Fe(III) system, the...
Effect of graphene oxide nanosheets on visible light-assisted antibacterial activity of vertically-aligned copper oxide nanowire arrays, Article Journal of Colloid and Interface Science ; Volume 521 , 2018 , Pages 119-131 ; 00219797 (ISSN) ; Ashari Astani, N ; Rahighi, R ; Tayyebi, A ; Tayebi, M ; Khezri, J ; Hashemi, E ; Rothlisberger, U ; Simchi, A ; Sharif University of Technology
Academic Press Inc 2018
In the present work, the effect of graphene oxide (GO) nanosheets on the antibacterial activity of CuO nanowire arrays under visible light irradiation is shown. A combined thermal oxidation/electrophoretic deposition technique was employed to prepare three-dimensional networks of graphene oxide nanosheets hybridized with vertically aligned CuO nanowires. With the help of standard antibacterial assays and X-ray photoelectron spectroscopy, it is shown that the light-activated antibacterial response of the hybrid material against gram-negative Escherichia coli is significantly improved as the oxide functional groups of the GO nanosheets are reduced. In order to explore the physicochemical...
Nonlinear hierarchical multiscale modeling of cortical bone considering its nanoscale microstructure, Article Journal of Biomechanics ; Volume 42, Issue 10 , 2009 , Pages 1560-1565 ; 00219290 (ISSN) ; Naghdabadi, R ; Sharif University of Technology
We have used a hierarchical multiscale modeling scheme for the analysis of cortical bone considering it as a nanocomposite. This scheme consists of definition of two boundary value problems, one for macroscale, and another for microscale. The coupling between these scales is done by using the homogenization technique. At every material point in which the constitutive model is needed, a microscale boundary value problem is defined using a macroscopic kinematical quantity and solved. Using the described scheme, we have studied elastic properties of cortical bone considering its nanoscale microstructural constituents with various mineral volume fractions. Since the microstructure of bone...
How does the axial ligand of cytochrome p450 biomimetics influence the regioselectivity of aliphatic versus aromatic hydroxylation?, Article Chemistry - A European Journal ; Volume 15, Issue 22 , 2009 , Pages 5577-5587 ; 09476539 (ISSN) ; Tahsini, L ; Nam, W ; Sharif University of Technology
The catalytic activity of highvalent iron-oxo active species of heme enzymes is known to be dependent on the nature of the axial ligand trans to the iron-oxo group. In a similar fashion, experimental studies on iron-oxo porphyrin biomimetic systems have shown a significant axial ligand effect on ethylbenzene hydroxylation, with an axial acetonitrile ligand leading to phenyl hydroxylation products and an axial chloride anion giving predominantly benzyl hydroxylation products. To elucidate the fundamental factors that distinguish this regioselectivity reversal in iron-oxo porphyrin catalysis, we have performed a series of density functional theory calculations on the hydroxylation of...