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In situ solid-phase microextraction and post on-fiber derivatization combined with gas chromatography-mass spectrometry for determination of phenol in occupational air
, Article Analytica Chimica Acta ; Volume 742 , 2012 , Pages 17-21 ; 00032670 (ISSN) ; Baghernejad, M ; Bagheri, H ; Sharif University of Technology
Elsevier
2012
Abstract
A method based on solid-phase microextraction (SPME) followed by on-fiber derivatization and gas chromatography-mass spectrometry detection (GC-MS) for determination of phenol in air was developed. Three different types of SPME fibers, polar and non-polar poly(dimethylsiloxane) (PDMS) and polyethylene glycol (PEG) were synthesized using sol-gel technology and their feasibility to the sampling of phenol were investigated. Different derivatization reagents for post on-fiber derivatization of phenol were studied. Important parameters influencing the extraction and derivatization process such as type of fiber coating, type and volume of derivatizing reagent, derivatization time and temperature,...
Single fault reliability analysis in FPGA implemented circuits
, Article Proceedings - International Symposium on Quality Electronic Design, ISQED, 19 March 2012 through 21 March 2012 ; March , 2012 , Pages 49-56 ; 19483287 (ISSN) ; 9781467310369 (ISBN) ; Mohammadi, K ; Attarsharghi, P ; Sharif University of Technology
2012
Abstract
Reliability analysis in FPGA implementation of logic circuits is an important issue in designing fault tolerant systems for faulty environments. In this paper an analytical method is developed for analyzing such systems. This method is based on signal probability propagation of faults from the location of appearance to final outputs of circuit. Single fault model is used for the faults occurred in routes and LUTs. In addition reconvergent fan-outs are handled using 16 correlation coefficients propagation approach. Experimental results show a good agreement between this method and Monte Carlo method for reliability analysis of MCNC benchmarks
Advantage of applying OSC to 1H NMR-based metabonomic data of celiac disease
, Article International Journal of Endocrinology and Metabolism ; Volume 10, Issue 3 , 2012 , Pages 548-552 ; 1726913X (ISSN) ; Fathi, F ; Darvizeh, F ; Zali, M. R ; Nejad, M. R ; Rostami, K ; Tafazzoli, M ; oskouie, A. A ; Mortazavi Tabatabaei, S. A ; Sharif University of Technology
2012
Abstract
Background: Celiac disease (CD) is a disorder associated with body reaction to gluten. After the gluten intake, an immune reaction against the protein occurs and damages villi of small intestine in celiac patients gradually. Objectives: The OSC, a filtering method for minimization of inter- and intra-spectrom-eter variations that influence on data acquisition, was applied to biofluid NMR data of CD patients. Patients and Methods: In this study, metabolites of total 56 serum samples from 12 CD patients, 15 CD patients taking gluten-free diet (GFD), and 29 healthy cases were analyzed using nuclear magnetic resonance (NMR) and associated theoretical analysis. Employ-ing ProMetab (version...
The estimation of formation permeability in a carbonate reservoir using an artificial neural network
, Article Petroleum Science and Technology ; Volume 30, Issue 10 , 2012 , Pages 1021-1030 ; 10916466 (ISSN) ; Masihi, M ; Fatholahi, S ; Sharif University of Technology
2012
Abstract
Reservoir permeability is an important parameter that its reliable prediction is necessary for reservoir performance assessment and management. Although many empirical formulas are derived regarding permeability and porosity in sandstone reservoirs, these correlations cannot be accurately depicted in carbonate reservoir for the wells that are not cored and for which there are no welltest data. Therefore, having a framework for estimation of these parameters in reservoirs with neither coring samples nor welltest data is crucial. Rock properties are characterized by using different well logs. However, there is no specific petrophysical log for estimating rock permeability; thus, new methods...
Multivariate variability monitoring using EWMA control charts based on squared deviation of observations from target
, Article Quality and Reliability Engineering International ; Volume 27, Issue 8 , 2011 , Pages 1069-1086 ; 07488017 (ISSN) ; Niaki, S. T. A ; Sharif University of Technology
Abstract
Recent research works have shown that control statistics based on squared deviation of observations from target have the ability to monitor variability in both univariate and multivariate processes. In the current research, the properties of the control statistic S t that has been proposed by Huwang et al. (J. Quality Technology 2007; 39:258-278) are first reviewed and three new S t-based multivariate schemes are then presented. Extensive simulation experiments are performed to compare the performances of the proposed schemes with those of the multivariate exponentially weighted mean squared deviation (MEWMS) and the L 1-norm distance of the MEWMS deviation from its expected value (MEWMSL 1)...
Comparison of mouse embryo deformation modeling under needle injection using analytical Jacobian, nonlinear least square and artificial neural network techniques
, Article Scientia Iranica ; Volume 18, Issue 6 , 2011 , Pages 1486-1491 ; 10263098 (ISSN) ; Ahmadian, M. T ; Vossoughi, G. R ; Sharif University of Technology
Abstract
Analytical Jacobian, nonlinear least square and three layer artificial neural network models are employed to predict deformation of mouse embryos under needle injection, based on experimental data captured from literature. The Maximum Absolute Error (MAE), coefficient of determination ( R2), Relative Error of Prediction (REP), Root Mean Square Error of Prediction (RMSEP), NashSutcliffe coefficient of efficiency ( Ef) and accuracy factor ( Af) are used as the basis for comparison of these three models. Analytical Jacobian, nonlinear least square and ANN models have yielded the correlation coefficient of 0.9985, 0.9964 and 0.9998, respectively. The REP between the models predicted values and...
A well-dispersed Pt/Ni/TiO 2 nanotubes modified electrode as an amperometric non-enzymatic glucose biosensor
, Article Sensor Letters ; Volume 9, Issue 5 , October , 2011 , Pages 1598-1605 ; 1546198X (ISSN) ; Luo, S ; Yang, L ; Mahshid, S ; Dolati, A ; Ghorbani, M ; Cai, Q ; Sharif University of Technology
2011
Abstract
In this study a novel Pt/Ni nanostructure consisting of nano-bushes and nanocubes was fabricated onto TiO 2 nanotubes. The scanning electron microscopy images showed that a large amount of well-dispersed nano-architectures had uniformly covered all over the surface which made an electrode with high surface area. It was obviously seen that the nanocube structures mainly consists of Ni had been grown on top of each other while the Pt colonies represented bush-like structures. As a non-enzymatic glucose biosensor, the Pt/Ni TiO 2 nanotubes modified electrode exhibited an excellent performance. The proposed biosensor had two linear ranges for detection of glucose from 0 to 0.12 mM (correlation...
Prediction of standard enthalpy of combustion of pure compounds using a very accurate group-contribution-based method
, Article Energy and Fuels ; Volume 25, Issue 6 , April , 2011 , Pages 2651-2654 ; 08870624 (ISSN) ; Mirkhani, S. A ; Tofangchi Mahyari, A. R ; Sharif University of Technology
2011
Abstract
The artificial neural network-group contribution (ANN-GC) method is applied to estimate the standard enthalpy of combustion of pure chemical compounds. A total of 4590 pure compounds from various chemical families are investigated to propose a comprehensive and predictive model. The obtained results show the squared correlation coefficient (R 2) of 0.999 99, root mean square error of 12.57 kJ/mol, and average absolute deviation lower than 0.16% for the estimated properties from existing experimental values
Prediction of absolute entropy of ideal gas at 298 K of pure chemicals through GAMLR and FFNN
, Article Energy Conversion and Management ; Volume 52, Issue 1 , 2011 , Pages 630-634 ; 01968904 (ISSN) ; Bagheri, M ; Ghaniyari-Benis, S ; Aslebagh, R ; Kamaloo, E ; Sharif University of Technology
2011
Abstract
Thermodynamical optimization for energy conversion system can be performed by decreasing entropy generation. For calculation of entropy, we need to know entropy of ideal gases at 298 K as a reference point. Entropy is a thermodynamic quantity which is not easily measured and prediction of entropy by molecular structures for new designed molecules may be a challenge. An easy and accurate equation for prediction of absolute entropy of pure ideal gas at 298 K was introduced for the first time based on the quantitative structure property relationship (QSPR) approach. Thousand seven hundred pure chemical compounds and 3224 molecular descriptors were used for finding this easy equation by genetic...
Is there a reliable and invariant set of muscle synergy during isometric biaxial trunk exertion in the sagittal and transverse planes by healthy subjects?
, Article Journal of Biomechanics ; Volume 48, Issue 12 , Sep , 2015 , Pages 3234-3241 ; 00219290 (ISSN) ; Mousavi, S. J ; Hadizadeh, M ; Narimani, R ; Khalaf, K ; Campbell Kyureghyan, N ; Parnianpour, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
It has been suggested that the central nervous system simplifies muscle control through basic units, called synergies. In this study, we have developed a novel target-matching protocol and used non-negative matrix factorization (NMF) technique to extract trunk muscle synergies and corresponding torque synergies. Isometric torque data at the L5/S1 level and electromyographic patterns of twelve abdominal and back muscles from twelve healthy participants (five females) were simultaneously recorded. Each participant performed a total number of 24 isometric target-matching tasks using 12 different angular directions and 2 levels of uniaxial and biaxial exertions. Within- and between-subject...
Test-retest reliability of Kinect's measurements for the evaluation of upper body recovery of stroke patients
, Article BioMedical Engineering Online ; Volume 14, Issue 1 , 2015 ; 1475925X (ISSN) ; Behzadipour, S ; Saadat, M ; Sharif University of Technology
BioMed Central Ltd
2015
Abstract
Background: Performance indices provide quantitative measures for the quality of motion, and therefore, assist in analyzing and monitoring patients' progress. Measurement of performance indices requires costly devices, such as motion capture systems. Recent developments of sensors for game controllers, such as Microsoft Kinect, have motivated many researchers to develop affordable systems for performance measurement applicable to home and clinical care. In this work, the capability of Kinect in finding motion performance indices was assessed by analyzing intra-session and inter-session test-retest reliability. Method: Eighteen stroke patients and twelve healthy subjects participated in this...
The effects of movement speed on kinematic variability and dynamic stability of the trunk in healthy individuals and low back pain patients
, Article Clinical Biomechanics ; Volume 30, Issue 7 , Aug , 2015 , Pages 682-688 ; 02680033 (ISSN) ; Sanjari, M. A ; Mokhtarinia, H. R ; Moeini Sedeh, S ; Khalaf, K ; Parnianpour, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Background: Comparison of the kinematic variability and dynamic stability of the trunk between healthy and low back pain patient groups can contribute to gaining valuable information about the movement patterns and neuromotor strategies involved in various movement tasks. Methods: Fourteen chronic low back pain patients with mild symptoms and twelve healthy male volunteers performed repeated trunk flexion-extension movements in the sagittal plane at three different speeds: 20 cycles/min, self-selected, and 40 cycles/min. Mean standard deviations, coefficient of variation and variance ratio as variability measures; maximum finite-time Lyapunov exponents and maximum Floquet multipliers as...
Structural image representation for image registration
, Article 2015 International Symposium on Artificial Intelligence and Signal Processing, AISP 2015, 3 March 2015 through 5 March 2015 ; March , 2015 , Pages 95-100 ; 9781479988174 (ISBN) ; Shirpour, M ; Manzuri, M. T ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
Image registration is an important task in medical image processing. Assuming spatially stationary intensity relation among images, conventional area based algorithms such as CC (Correlation Coefficients) and MI (Mutual Information), show weaker results alongside spatially varying intensity distortion. In this research, a structural representation of images is introduced. It allows us to use simpler similarity metrics in multimodal images which are also robust against the mentioned distortion field. The efficiency of this presentation in non-rigid image registration in the presence of spatial varying distortion field is examined. Experimental results on synthetic and real-world data sets...
Design and evaluation of a novel triaxial isometric trunk muscle strength measurement system
, Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 223, Issue 6 , 2015 , Pages 755-766 ; 09544119 (ISSN) ; Farahmand, F ; Meghdari, A ; Vossoughi, G ; Parnianpour, M ; Sharif University of Technology
SAGE Publications Ltd
2015
Abstract
Maximal strength measurements of the trunk have been used to evaluate the maximum functional capacity of muscles and the potential mechanical overload or overuse of the lumbar spine tissues in order to estimate the risk of developing musculoskeletal injuries. A new triaxial isometric trunk strength measurement system was designed and developed in the present study, and its reliability and performance was investigated. The system consisted of three main revolute joints, equipped with torque sensors, which intersect at L5 - S1 and adjustment facilities to fit the body anthropometry and to accommodate both symmetric and asymmetric postures in both seated and standing positions. The dynamics of...
Test-retest reliability of postural stability measures during quiet standing in patients with a history of nonspecific low back pain
, Article Biomedical Engineering - Applications, Basis and Communications ; Volume 22, Issue 3 , 2010 , Pages 255-262 ; 10162372 (ISSN) ; Salavati, M ; Negahban, H ; Parnianpour, M ; Sharif University of Technology
2010
Abstract
As balance is the foundation for all voluntary motor skills, considerable research has been conducted to evaluate postural control in patients with low back pain (LBP). Although reliability is a population-specific property, to the authors' knowledge, there has been no study to determine the test-retest reliability of the center of pressure (COP) measures in the general population of LBP patients. As many as 11 patients with a history of nonspecific LBP randomly completed postural measurements with three levels of difficulty (rigid surface-eyes open, rigid surface-eyes closed, and foam surface-eyes closed) in two sessions. The COP data were used to calculate standard deviation of amplitude,...
Reliability and validity of the Persian version of Foot and Ankle Ability Measure (FAAM) to measure functional limitations in patients with foot and ankle disorders
, Article Osteoarthritis and Cartilage ; Volume 18, Issue 6 , 2010 , Pages 755-759 ; 10634584 (ISSN) ; Salavati, M ; Negahban, H ; Sohani, S. M ; Taghizadeh, F ; Feizi, A ; Karimi, A ; Parnianpour, M ; Sharif University of Technology
2010
Abstract
Objective: To translate the Foot and Ankle Ability Measure (FAAM) into Persian and to evaluate the psychometric properties of the Persian version of FAAM. Methods: 93 patients with a range of foot and ankle disorders, completed the Persian version of the FAAM and Short-Form 36 Health Survey (SF-36) in the test session. With an interval of 2-6 days, 60 patients filled out the FAAM in the retest session. The FAAM is composed of two subscales including activities of daily living (ADL) and SPORTS. Internal consistency was assessed using Cronbach's alpha, test-retest reliability using intraclass correlation coefficient (ICC) and standard error of measurement (s.e.m.), item internal consistency...
Membrane interactions control residue fluctuations of outer membrane porins
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 81, Issue 5 , May , 2010 ; 15393755 (ISSN) ; Mobasheri, H ; Ejtehadi, M. R ; Sharif University of Technology
2010
Abstract
Bacterial outer membrane porins (Omp) that have robust β -barrel structures, show potential applications for nanomedicine devices in synthetic membranes and single molecule detection biosensors. Here, we explore the conformational dynamics of a set of 22 outer membrane porins, classified into five major groups: general porins, specific porins, transport Omps, poreless Omps and composed pores. Normal mode analysis, based on mechanical vibration theory and elastic network model, is performed to study the fluctuations of residues of aforementioned porins around their equilibrium positions. We find that a simple modification in this model considering weak interaction between protein and...
Effects of structural configuration on vibration control of smart laminated beams under random excitations
, Article Journal of Mechanical Science and Technology ; Volume 24, Issue 5 , 2010 , Pages 1119-1125 ; 1738494X (ISSN) ; Sharif University of Technology
Abstract
The influence of structural configuration on vibration responses of smart laminated beams under random loading is studied. The effect of laminate configurations and locations of sensors/actuators in the smart system is also investigated. The layer-wise approximation for displacement and electric potential is utilized to construct the finite element model. The closed-loop control response is determined through an optimal control algorithm based on the Linear Quadratic Regulator (LQR). The correlation coefficient between the input random force and the applied actuating voltage for various configurations is also computed. It is revealed that for softer configurations, the correlation...
Reliability and validity of the Foot and Ankle Outcome Score: A validation study from Iran
, Article Clinical Rheumatology ; Volume 29, Issue 5 , 2010 , Pages 479-486 ; 07703198 (ISSN) ; Mazaheri, M ; Salavati, M ; Sohani, S. M ; Askari, M ; Fanian, H ; Parnianpour, M ; Sharif University of Technology
2010
Abstract
The aims of this study were to culturally adapt and validate the Persian version of Foot and Ankle Outcome Score (FAOS) and present data on its psychometric properties for patients with different foot and ankle problems. The Persian version of FAOS was developed after a standard forward-backward translation and cultural adaptation process. The sample included 93 patients with foot and ankle disorders who were asked to complete two questionnaires: FAOS and Short-Form 36 Health Survey (SF-36). To determine test-retest reliability, 60 randomly chosen patients completed the FAOS again 2 to 6 days after the first administration. Test-retest reliability and internal consistency were assessed using...
Prediction of CO2-oil molecular diffusion using adaptive neuro-fuzzy inference system and particle swarm optimization technique
, Article Fuel ; Volume 181 , 2016 , Pages 178-187 ; 00162361 (ISSN) ; Sahebi, H ; Ghiasi, M. M ; Mirjordavi, N ; Esmaeilzadeh, F ; Lee, M ; Bahadori, A ; Sharif University of Technology
Elsevier Ltd
Abstract
The quantification of carbon dioxide (CO2) dissolution in oil is crucial in predicting the potential and long-term behavior of CO2 in reservoir during secondary and tertiary oil recovery. Accurate predicting carbon dioxide molecular diffusion coefficient is a key parameter during carbon dioxide injection into oil reservoirs. In this study a new model based on adaptive neuro-fuzzy inference systems (ANFIS) is designed and developed for accurate prediction of carbon dioxide diffusivity in oils at elevated temperature and pressures. Particle Swarm Optimization (PSO) as population based stochastic search algorithms was applied to obtain the optimal ANFIS model parameters. Furthermore, a simple...