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Parametric study of droplet size in an axisymmetric flow-focusing capillary device

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Chinese Journal of Chemical Engineering 2020年第4期28卷 1016-1022页

作者： mostafa Rahimi Sajad Yazdanparast Pouya Rezai Department of Mechanical Engineering University of Mohaghegh ArdabiliArdabilIran Department of Mechanical Engineering York UniversityTorontoONCanada

A conventional technique for microfluidic droplet generation is Co-axial flow focusing(Cff)in which a contraction zone is placed downstream of the dispersed phase *** this contraction zone,the dispersed-phase(dphase)fluid is pinched off by continuous-phase(c-phase)fluid to generate *** the influence of multiple parameters such as the fluids velocities and viscosities,the interfacial tension,and nozzle and orifice diameters on the droplet size is of great importance for the design and application of Cff ***,development of more complete numerical models is *** this paper,we show our model is compatible with experimental data and then numerically investigate the effects of aforementioned parameters on the droplet generation in a Cff microfluidic *** results showed that the c-phase flow rate,viscosity and the interfacial tension had great impacts on the droplet *** effect of the nozzle diameter on the generated droplet size was small compared to that of the orifice in a Cff *** the simulation results,a correlation was also developed and suggested which predicts the droplet size with less than 15%error in a wide range of the introduced dimensionless parameters.

关键词： Co-axial flow focusing Microfluidics Droplet generation Numerical investigation

Self-Tuning Parameters for Decision Tree Algorithm Based on Big Data Analytics

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计算机、材料和连续体（英文） 2023年第4期75卷 943-958页

作者： Manar Mohamed Hafez Essam Eldin f.Elfakharany Amr A.Abohany mostafa Thabet College of Computing and Information Technology Arab Academy for ScienceTechnology&Maritime TransportCairoEgypt faculty of Computers and Information Kafrelsheikh UniversityKafrelsheikhEgypt faculty of Computers and Information Fayoum UniversityFayoumEgypt

Big data is usually unstructured, and many applications require theanalysis in real-time. Decision tree (DT) algorithm is widely used to analyzebig data. Selecting the optimal depth of DT is time-consuming process as itrequires many iterations. In this paper, we have designed a modified versionof a (DT). The tree aims to achieve optimal depth by self-tuning runningparameters and improving the accuracy. The efficiency of the modified (DT)was verified using two datasets (airport and fire datasets). The airport datasethas 500000 instances and the fire dataset has 600000 instances. A comparisonhas been made between the modified (DT) and standard (DT) with resultsshowing that the modified performs better. This comparison was conductedon multi-node on Apache Spark tool using Amazon web services. Resultingin accuracy with an increase of 6.85% for the first dataset and 8.85% for theairport dataset. In conclusion, the modified DT showed better accuracy inhandling different-sized datasets compared to standard DT algorithm.

关键词： Big data classification decision tree Amazon web services

Effects of Avian Wings Color Patterns on Their flight Performance:Experimental and Computational Studies

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Journal of Bionic Engineering 2023年第2期20卷 683-710页

作者： Ahmed Aboelezz Brenden Herkenhoff mostafa Hassanalian Department of Mechanical Engineering New Mexico Institute of Mining and TechnologySocorroNM87801USA

There are many theories behind the colors of a bird’s *** of these theories point to the color’s purpose to attract mates and hide from *** recent investigations concluded that the dark colors of birds help in reducing the drag force during flight.A new theory is presented in the current research,which states that a bird's dark color not only reduces the drag,but the color pattern also improves the overall flight performance,and each color pattern has a different type of flight performance *** difference in improvement is a result of variation in hot and cold surfaces on the bird skin as a result of the variation between light and dark feather *** prove this new theory,thermal images were captured of real bird wings under the effect of infrared ***,a novel wind tunnel wing with the ability to adjust the temperature in desired locations and patterns on the wing’s surface was manufactured and tested to evaluate the effect of aerodynamics forces as a function in the surface temperature and the hot–cold *** collected data from this wing showed potential flight efficiency improvements of 20%,comparing the lift-to-drag ratio for specific heating cases,which could increase the flight *** considering lift and drag,there were specific heating cases with corresponding angles of attack in which these parameters improved by up to 20%and 7%,*** heating cases could increase the lift at a low angle of attack,which is helpful in cruise flight performance,while some cases could increase the maximum lift coefficient by 6%.This is very helpful in lowering stall and the minimum flight ***,some cases could increase the lift-to-drag ratio,which led to an increase in the flight *** better understand the effect of the various patterns,computational fluid dynamics(CfD)simulations were conducted on the *** new theory was proved based on the CfD results and verified through the success

关键词： Aerodynamic loads CfD Drag Heated boundary layer Surface temperature

Design of on-board calibration methods for a digital sun sensor based on Levenberg–Marquardt algorithm and Kalman filters

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Chinese Journal of Aeronautics 2020年第1期33卷 339-351页

作者： Ali RAHDAN Hossein BOLANDI mostafa ABEDI Department of Electrical Engineering Iran University of Science&TechnologyTehran ***Iran Department of Electrical Engineering Shahid Beheshti UniversityTehran ***Iran

Digital sun sensor is one of the most important sensors used in the Attitude Determination System(ADS)of the *** to the harsh environmental conditions that exist in the space,various distortions may occur in the sun sensor optical system that lead to the reduced accuracy of this ***,it is necessary to recalibrate the optical parameters of the aforementioned *** this purpose,first a novel attitude independent error model is proposed for the SS-411 sun sensor that includes the central point of the CCD array,installation error,filter thickness and sensor ***,the mutual interfaces between the sensor parameters are considered in the developed *** order to extract the sensor parameters,a nonlinear optimization technique called the Levenberg–Marquardt is applied to the developed model as a batch *** addition,the Extended Kalman filter(EKf)and the Unscented Kalman filter(UKf)have been utilized as sequential *** will be shown that by considering a worst case of variation amount for sensor parameters,an accuracy improvement of about 17°is achieved by the developed calibration *** between the developed algorithms represents that UKf has higher accuracy,shorter time convergence but higher computational load.

关键词： Digital sun sensor Extended Kalman filter Levenberg–Marquardt On-board calibration Unscented Kalman filter

In vitro propagation of conifers using mature shoots

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Journal of forestry Research 2018年第3期29卷 565-574页

作者： mostafa K.Sarmast Department of Horticultural Science Faculty of Plant Production Gorgan University of Agricultural Sciences and Natural Resources (GUASNR)

Micropropagation mostly leads to the production of innumerable true-to-type plants. However, establishing pathogen-free explants through in vitro culture requires a precise management of time for the exposure of explants to antimicrobial chemicals. The application of antimicrobial chemicals must also be managed to impose the least injury on explants. This review discusses the contributions of micropropagation procedures, explant types, subculture duration, media ingredients and plant growth regulators to the in vitro response of conifer explants. Even though regeneration from mature conifer explants such as mature shoots are laborious, the chances of variation, induced in vitro, are unlikely.

关键词： Conifers Decontamination Micropropagation Tissue culture

A Multi-factor Authentication-Based framework for Identity Management in Cloud Applications

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Computers, Materials & Continua 2022年第5期71卷 3193-3209页

作者： Wael Said Elsayed mostafa M.M.Hassan Ayman Mohamed mostafa faculty of Computers and Informatics Zagazig UniversityZagazig44519Egypt College of Computer and Information Sciences Jouf UniversitySakaka72314Saudi Arabia

User’s data is considered as a vital asset of several *** data to the cloud computing is not an easy decision for any organization due to the privacy and security *** providers must ensure that both data and applications that will be stored on the cloud should be protected in a secure *** data stored on the public cloud will be vulnerable to outside and inside *** paper provides interactive multi-layer authentication frameworks for securing user identities on the *** access control policies are applied for verifying users on the cloud.A security mechanism is applied to the cloud application that includes user registration,granting user privileges,and generating user authentication *** intrusion detection system is embedded to the security mechanism to detect malicious *** multi factor authentication,intrusion detection,and access control techniques can be used for ensuring the identity of the ***,encryption techniques are used for protecting the data from being *** results are carried out to verify the accuracy and efficiency of the proposed frameworks and *** results recorded high detection rate with low false positive alarms.

关键词： Cloud computing service providers multi-layer authentication frameworks and access control

Biodiversity of arbuscular mycorrhizal fungi in Amygdalus scoparia Spach plantations and a natural stand

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Journal of forestry Research 2017年第6期28卷 1203-1211页

作者： Javad Mirzaei mostafa Moradi Department of forest Science Faculty of AgricultureUniversity of Ilam P.O. Box 69315516 Ilam Iran Department of forestry Faculty of Environment and Natural Resources Behbahan Khatam Al-Anbia University of Technology P.O. Box *** Behbahan KhuzestanIran

The biodiversity of arbuscular mycorrhizal fungi(AMf) was surveyed in the Kolm region of Iran in three adjacent sites, a natural stand, a 10-year-old and a 15-yearold plantation of Amygdalus scoparia. To date, there have been few studies of AMf biodiversity in Iran, especially in the western forests of the country. for this study, soil and root samples were taken from A. scoparia rhizosphere soil in spring and autumn. Almost half of the root length was colonized by AMf. We identified 13 AMf species belonging to Glomeraceae, Claroideoglomeraceae or Diversisporaceae. The three plantations differed in terms of soil electrical conductivity, organic C and P. Spore density was significant correlated with P concentration. Root length colonization was correlated only with soil *** diversity and richness were significantly correlated with soil N, P, organic C and spore density. AMf diversity in 15-year-old plantations was more similar to that in the natural stand than in the 10-year-old plantation. We confirmed that a 15-year-old plantation is not similar in terms of AMf colonization to natural stands. We conclude that more than 15 years are required for AMf colonization of plantations to resemble that of natural stands.

关键词： Arbuscular mycorrhizal Amygdalus scoparia Biodiversity

Neutronic design investigation of a liquid injection-based second shutdown system for a typical research reactor using MCNPX

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Nuclear Science and Techniques 2018年第3期29卷 51-60页

作者： Ehsan Boustani mostafa Hassanzadeh Nuclear Science and Technology Research Institute (NSTRI) Reactor and Nuclear Safety School

Safety systems, built on state-of-the-art technology, are essential for achieving acceptable levels of plant safety to minimize hazards to the reactor and the general public. The second shutdown system(SSS) as an engineered safety feature and a part of the reactor protection system(RPS) is a means for rapidly shutting down a nuclear reactor, keeping it in a subcritical state and serving as a backup to the first shutdown system(fSS). In this research, one SSS with two types of optimum chamber designs is proposed that take into account the main current characteristic features of the Tehran research reactor with improvements over earlier designs. They are based on a liquid neutron absorber injection that is preferably different, diverse, and independent from the fSS based on the rod drop mechanism. The major design characteristics of this SSS with two different chambers were investigated using MCNPX 2.6.0 code. The performed calculations showed that the designed SSS is a reliable shutdown system, assuring an appropriate shutdown margin and injection time, with no significant effects on the effective delayed neutron fraction while causing minimal variations to the core structure. further, the reasonable financial cost and the prolongation of the operation cycle are additional advantages of this design.

关键词： Tehran research reactor Second shutdown system Nuclear safety Design criteria MCNPX code

Multimodality image registration and fusion using neural network

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Journal of Harbin Institute of Technology(New Series) 2003年第3期10卷 235-240页

作者： mostafa G mostafa Aly A farag Edward Essock Computer Vision and Image Processing Laboratory Dept. of Electrical and Computer Engineering University of Louisville Louisville KY 40292 USAComputer Vision and Image Processing Laboratory Dept. of Electrical and Computer Engineering University of Louisville Louisville KY 40292 USADept. of Psychology University of Louisville Louisville kY 40292 USA

Multimodality image registration and fusion are essential steps in building 3-D models from remotesensing data. We present in this paper a neural network technique for the registration and fusion of multimodali-ty remote sensing data for the reconstruction of 3-D models of terrain regions. A feedforward neural network isused to fuse the intensity data sets with the spatial data set after learning its geometry. Results on real data arepresented. Human performance evaluation is assessed on several perceptual tests in order to evaluate the fusionresults.

关键词： data fusion image registration image interpolation neural network, 3-D model building