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Analytical Study on the Rate of Sound Transmission Loss in Single Row Honeycomb Sandwich Panel Using a Numerical Method

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Sound & Vibration 2020年第2期54卷 127-137页

作者： Rohollah Fallah Madvari mohammad reza monazzam Mohsen Niknam Sharak Mohsen Mosa Farkhani Student Research Committee Department of Occupational Health EngineeringSchool of Public Health and SafetyShahid Beheshti University of Medical SciencesTehranIran Department of Occupational Health Engineering School of Public HealthTehran University of Medical SciencesTehranIran Department of Mechanical Engineering University of BirjandBirjandIran

Honeycomb structures have recently,replaced with conventional homogeneous *** the fact that sandwich panels containing a honeycomb core are able to adjust geometric parameters,including internal angles,they are suitable for acoustic control *** main objective of this study was to obtain a transmission loss curve in a specific honeycomb frequency range along with same overall dimensions and *** this study,a finite element model(FEM)in ABAQUS software was used to simulate honeycomb panels,evaluate resonant frequencies,and for acoustic *** model was used to obtain acoustic pressure and then to calculate the sound transmission loss(STL)in MATLAB *** and acoustic analysis of panels were performed in the frequency range of 1 to 1000 *** models analyzed in this design includes 14-single row-honeycomb designs with angles of−45°,−30°,−15°,0°,+15°,+30°,+45°.The results showed that a-single row and−45°cell angle honeycomb panel in the frequency range of 1 to 1000 Hz had the highest STL as well as the highest number of frequency modes(90 mods).Furthermore,the panel had the highest STL regarding the area under the STL curve(dB∙Hz).The panels containing more frequency mods,have a higher transmission ***,the sound transmission loss is more sensitive to the cell angle variable(θ).In other studies,the STL was more sensitive to the number of honeycomb cells in the horizontal and vertical directions,as well as the angle of cells.

关键词： Finite element model honeycomb sound transmission loss

Presenting a Signal to Noise Ratio Model Based on the Combined Effect ofSound Pressure Level/frequency, Exposure Time and Oral Potassium:Experimental Study in Rats

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Sound & Vibration 2020年第1期54卷 17-25页

作者： Parvin Nassiri Sajad Zare mohammad reza monazzam Akram Pourbakht Rasoul Hemmatjo Hossein ElahiShirvan Department of Occupational Health School of Public HealthTehran University of Medical SciencesTehranIran Student Research Committee Kerman University of Medical ScienceKermanIran Department of Audiology School of RehabilitationIran University of Medical SciencesTehranIran Department of Occupational Health School of Public HealthUrmia University of Medical SciencesUrmiaIran

Exposure to noise can lead to anatomical,nonauditory,and auditory *** auditory influence of noise exposure is manifested in the form of Noise-induced hearing loss(NIHL).The current study aimed at present a signal to noise ratio model of otoacoustic emission of rats’ears in the light of the combined effect of sound pressure level,sound frequency,exposure time,and potassium concentration of the used *** total,36 adult male rates,whose age varied from 3 to 4 months and had a weight of 200±50 g,were randomly divided into 12 groups,with each group consisting of 3 *** rats in both groups(case and control groups)were exposed to SPLs of 85,95,and 105 dB,emitted from sources that generated white noise.A distortion product otoacoustic emission(DPOAE)machine(4000 I/O manufactured by Homoth of Germany)was utilized to gauge the signal to noise ratio(SNR)of otoacoustic emissions of rats’ears at various frequencies in an acoustic *** inclusion criterion was SNR≥6 *** collected data were fed into the Statistical Package for Social Sciences(SPSS)version 18,followed by conducting descriptive and inferential data analysis *** results of SNR analysis indicated that over 82%of all data had SNRs that were equal to or greater than 6 *** data were considered as acceptable ***,SPL and sound frequency had significant associations with SNR(P<0.0001).Exposure time also significantly correlated with SNR(P=0.008).However,the potassium concentration of the used water had no significant correlation with SNR(P=0.97).High sound pressure levels result in lower ***,higher frequency leads to higher *** the contrary,longer exposure time reduces ***,the potassium concentration of the used water has no effect on SNR.

关键词： Noise sound pressure level potassium DPOAE rat

Stabilizing silica nanoparticles in high saline water by using polyvinylpyrrolidone for reduction of asphaltene precipitation damage under dynamic condition

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Chinese Journal of Chemical Engineering 2019年第5期27卷 1021-1029页

作者： mohammad reza Aghajanzadeh mohammad Sharifi Department of Petroleum Engineering Amirkabir University of Technology

In this study, the performance of stable nanofluid containing SiO2 nanoparticles dispersed and stabilized in high salinity brine for asphaltene inhibition in dynamic condition is evaluated. In the first stage of this work, the stability of silica nanoparticles in different range of water salinity(0–100000 mg·L-1) is investigated. Next, stable nanofluid containing highest salinity is selected as asphaltene inhibitor agent to inject into the damaged core sample. The estimated values of oil recovery for base case, after damage process and after inhibition of asphaltene precipitation using nanofluid are 51.6%, 36.1% and 46.7%, respectively. The results showed the reduction in core damage after using nanofluid. In addition, the relative permeability curves are plotted for the base case, after damage process and also after inhibition of asphaltene precipitation using nanofluid. Comparison of relative permeability curves shows, relative permeability of oil phase decreased after damage process as compared with the base case. But after using nanofluid the oil relative permeability curve has shifted to the right and effective permeability of oil phase has been improved.

关键词： Formation damage Enhanced oil recovery Salinity Asphaltene Core flooding Nano particles

Experimental investigation of different brines imbibition influences on co-and counter-current oil flows in carbonate reservoirs

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Chinese Journal of Chemical Engineering 2021年第5期34卷 17-29页

作者： Pouyan Ahmadi mohammad reza Aghajanzadeh Masoud Riazi mohammad reza Malayeri mohammad Sharifi Enhanced Oil Recovery(EOR)Research Centre IOR/EOR Research InstituteShiraz UniversityShirazIran Helmholtz Centre for Environmental Research-UFZ LeipzigGermany Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Institut für Verfahrenstechnik und Umwelttechnik Technische Universität DresdenGermany

Imbibition of water,as wetting phase in oil-wet fractured carbonate reservoirs,plays a key role in fluid flow between matrix and fracture *** type of injected seawater and its chemistry would profoundly influence the imbibition *** this study,the impact of smart water(a brine that its ions have been adjusted to facilitate oil recovery)and low salinity water on co-and counter-current imbibition processes for oil-wet carbonate cores has been experimentally *** results show an increase of about 10% in oil recovery for co-and counter-currents for smart seawater imbibition compared to that of low salinity *** addition,as a result of the influence of co-and counter-current on each other,by co-current removal from one core face,the countercurrent in the other face would be intensified by as much as about 75%.A close examination of different lengths(5,7 and 9 cm)of carbonate cores with the same permeability revealed that by decreasing porous medium length,the amount of counter-current producing oil would be decreased so that in the 5 cm core,counter current oil production will not *** similar core lengths by increasing permeability,the share of counter current flow would be decreased approximately 18% since the capillary pressure could not overcome non-wetting phase viscous *** the role of matrix length along with a modified brine(which is designed according to the matrix mixture)strengthen the relevant mechanisms to have more oil production so that the higher thickness of matrix causes the higher amount of co-current oil producing and consequently more total recovery.

关键词： Smart water Co-current Counter current Wettability alteration Oil recovery

Stochastic price based coordinated operation planning of energy storage system and conventional power plant

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Journal of Modern Power Systems and Clean Energy 2019年第5期7卷 1020-1032页

作者： mohammad reza SHEIBANI Gholam reza YOUSEFI mohammad Amin LATIFY Department of Electrical and Computer Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran

A generation company(GENCO)which has a conventional power plant(CPP)intends to add an energy storage system(ESS)beside the CPP to increase its flexibility and *** this purpose,a new model is proposed for coordinated operation planning of the CPP and ESS in energy and spinning reserve markets in the presence of a bilateral *** proposed model is based on the stochastic price based unit commitment(PBUC)and price based storage commitment(PBSC).The uncertainties of the energy and spinning reserve prices and delivery requests in the spinning reserve market are modeled via scenarios based upon historical *** proposed model maximizes the profitability of the ESS beside the CPP and encourages the GENCO to invest the *** technology options to use beside the CPP are determined by economic *** results show that utilization of ESSs improves the technical operation of CPPs,as well as GENCOs’profitability.

关键词： Energy storage system Conventional power plant Operation planning Price based unit commitment

Enhanced empirical models for predicting the drift capacity of less ductile RC columns with flexural,shear,or axial failure modes

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Frontiers of Structural and Civil Engineering 2019年第5期13卷 1251-1270页

作者： mohammad reza AZADI KAKAVAND reza ALLAHVIRDIZADEH Unit of Strength of Materials and Structural Analysis Institute of Basic Sciences in Engineering SciencesUniversity of InnsbruckInnsbruck 6020Austria ISISE Department of Civil EngineeringUniversity of MinhoGuimaraes 4800-058Portugal

Capacity of components subjected to earthquake actions is still a widely interesting research topic. Hence, developing precise tools for predicting drift capacities of reinforced concrete (RC) columns is of great interest. RC columns are not only frequently constructed, but also their composite behavior makes the capacity prediction a task faced with many uncertainties. In the current article, novel empirical approaches are presented for predicting flexural, shear and axial failure modes in RC columns. To this aim, an extensive experimental database was created by collecting outcomes of previously conducted experimental tests since 1964, which are available in the literature. It serves as the basis for deriving the equations for predicting the drift capacity of RC columns by different regression analyses (both linear with different orders and nonlinear). Furthermore, fragility curves are determined for comparing the obtained results with the experimental results and with previously proposed models, like the ones of ASCE/SEI41-13. It is demonstrated that the proposed equations predict drift capacities, which are in better agreement with experimental results than those computed by previously published models. In addition, the reliability of the proposed equations is higher from a probabilistic point of view.

关键词： flexural-shear-axial failure drift capacity reinforced concrete columns statistical analysis fragility curves

Evaluation of attraction terms in equations of state on the prediction of solubility of some biomolecules in supercritical carbon dioxide

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Chinese Chemical Letters 2009年第4期20卷 501-505页

作者： mohammad reza Bozorgmehr mohammad reza Housaindokht Department of Chemistry Faculty of Science.Islamic Azad UniversityMashad BranchMashhadIran Department of Chemistry Faculty of ScienceFerdowsi University of MashhadMashadIran

In the present work, effect of the attraction terms of four recently modified Peng-Robinson （MPR） equations of state on the prediction of solubility of caffeine, cholesterol, uracil and erythromycin was studied. The attraction terms of two of these equations are linear relative to the acentric factor and for the other two are exponential. It is found that the later show less deviation. Also interaction parameters for the studied systems are obtained and the percentage of average absolute relative deviation （%AARD） in each calculation is displayed.

关键词： Equation of state Solubility Supercritical carbon dioxide Biomolecules

Proportional integral derivative controller design using Legendre orthogonal functions

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Journal of Central South University 2016年第10期23卷 2616-2629页

作者： reza Moradi mohammad Tabatabaei Department of Electrical Engineering Khomeinishahr Branch Islamic Azad University

The Legendre orthogonal functions are employed to design the family of PID controllers for a variety of plants. In the proposed method, the PID controller and the plant model are represented with their corresponding Legendre series. Matching the first three terms of the Legendre series of the loop gain with the desired one gives the PID controller parameters. The closed loop system stability conditions in terms of the Legendre basis function pole(λ) for a wide range of systems including the first order, second order, double integrator, first order plus dead time, and first order unstable plants are obtained. For first order and double integrator plants, the closed loop system stability is preserved for all values of λ and for the other plants, an appropriate range in terms of λ is obtained. The optimum value of λ to attain a minimum integral square error performance index in the presence of the control signal constraints is achieved. The numerical simulations demonstrate the benefits of the Legendre based PID controller.

关键词： PID controllers orthogonal functions legendre functions moment matching PI controller PD controller

Robust Control of Robotic Manipulators in the Task-Space Using an Adaptive Observer Based on Chebyshev Polynomials

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Journal of Systems Science & Complexity 2020年第5期33卷 1360-1382页

作者： GHOLIPOUR reza FATEH mohammad Mehdi Department of Electrical and Robotic Engineering Shahrood University of Technology*** ShahroodIran

In this paper,an adaptive observer for robust control of robotic manipulators is *** lumped uncertainty is estimated using Chebyshev ***,the uncertainty upper bound is required in designing observer-controller ***,obtaining this bound is a challenging *** solve this problem,many uncertainty estimation techniques have been proposed in the literature based on neuro-fuzzy *** an alternative,in this paper,Chebyshev polynomials have been applied to uncertainty estimation due to their simpler structure and less computational *** on strictly-positive-rea Lyapunov theory,the stability of the closed-loop system can be *** Chebyshev coefficients are tuned based on the adaptation rules obtained in the stability ***,to compensate the truncation error of the Chebyshev polynomials,a continuous robust control term is designed while in previous related works,usually a discontinuous term is *** SCARA manipulator actuated by permanent magnet DC motors is used for computer *** results reveal the superiority of the designed method.

关键词： Adaptive observer Chebyshev polynomials electrically driven robot manipulators robust control uncertainty estimation