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CFD investigation of the agitation in the desupersaturation during the wet-process phosphoric acid(WPPA)process

Chinese Journal of Chemical Engineering 2020年第8期28卷 2064-2074页

作者： Asmaa Hadane Lhachmi Khamar saad Benjelloun Abderrahman Nounah Mohammed Khamar LGCE Higher School of Technology in SaléMohammed V University in RabatMorocco MSDA Mohammed 6th Polytechnic UniversityBenguerir 43150Morocco LIPIM National School of Applied sciences in KhouribgaSultan Moulay Sliman University in Beni MellalMorocco

Desupersaturation is a complex cooling operation that involves hydrodynamic,thermal and mechanical *** process requires continuous agitation to avoid fouling problems and sludge *** current work aims to investigate the well mixedness in the desupersaturation tank for optimal *** this purpose,a multi-fluid CFD study was conducted based on the Euler–Euler modeling approach,considering a multiphase flow involving a liquid phase(phosphoric acid)and a poly-dispersed solid phase,i.e.a sludge with three different sizes where each size is considered as a separate ***,the hydrodynamic behavior of the flow within the agitated desupersaturator is analyzed through the investigation of the velocity fields as well as the power and pumping numbers,to determine both the agitator capacity to pump the flow and its power consumption during the ***,in order to assess the mixture homogeneity,we evaluated the solid suspension in the desupersaturation reactor following conventional methods and two new proposed methodologies:the first approach is to evaluate the suspension quality in the mixing system by compartment and the second consists on the assessment of the uniform convergence of the solid ***,we calculated the time required to achieve a full suspension at different solid *** other hand,we conducted a detailed analysis of the solid distribution dependency on the impeller rotational speed at different solid volume fraction,which allows a good understanding of the parameters controlling the homogenization in the desupersaturator.

关键词： CFD Multiphase flow Mass transfer Phosphoric acid Agitation

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CNTs/CNF-supported multi-active components as highly efficient bifunctional oxygen electrocatalysts and their applications in zincair batteries

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Nano Research 2023年第4期16卷 4793-4802页

作者： Weiyuan Ding Ali saad Yuchen Wu Zhiwei Wang Xiuting Li Institute for Advanced Study Shenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China

Rational construction of active components has been the biggest challenge in preparing efficient bifunctional oxygen ***,electrospinning and chemical vapor deposition(CVD)were employed to embed active species including FeCo nanoparticles,MNx(M=Fe,Co),and FePx in porous and graphitized carbon nanotubes(CNTs)/carbon nanofiber(CNF).The as-prepared FeCo@CoNx@FePx/C exhibited a half-wave potential as high as 0.86 V in oxygen reduction reaction(ORR)and low oxygen evolution reaction(OER)overpotential of 368 mV at 10 mA·cm^(−2),which are superior to Pt/C(0.83 V)and IrO_(2)(375 mV)*** assembled Zn-air battery(ZAB)showed a high energy efficiency(Edischarge/Echarge)of 65%at 20 mA·cm^(−2)and stabilized for 700 charge-discharge *** spectroscopic and microscopic characterizations evidenced that the outstanding bifunctionality of the electrocatalyst can be ascribed to three main reasons:First,FeCo nanoparticles are rich in MOH/MOOH active sites for OER,and FePx/CNTs constructed with CVD also modulate electronic structure to improve electron transfer;second,both MNx in carbon matrix and FePx/CNTs are highly active towards ORR;third,the CNTs/CNF are highly porous and graphitized,which promotes mass transport and improves electrical conductivity and stability of the *** work gives important implications on the design of bifunctional electrocatalysts.

关键词： carbon nanotubes(CNTs)/carbon nanofiber(CNF)-supported multi-active components oxygen reduction reaction oxygen evolution reaction zinc-air battery

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Cross Flow Characteristics and Heat Transfer of Staggered Tubes Bundle: A Numerical Study

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Frontiers in Heat and Mass Transfer 2023年第1期21卷 367-383页

作者： Husam Rashid Hudear saad Najeeb Shehab Department of Mechanical Engineering College of EngineeringMustansiriyah UniversityBaghdadIraq

This paper presents a numerical emulation study of heat transmission through tube banks in *** configuration is displayed by fluid dynamics using computer programs(CFD)software(ANSYS fluent).The computer model is used to predict the values of the Nusselt number when changing the values of heat flux and longitudinal *** longitudinal pitch(SL/D)of 1.3,1.8,and 2.4 *** transverse pitch(ST/D)of 1.5 mm,and also considered Reynolds numbers 10000,13000,17000,and *** staggered configuration of the tube bundle is demonstrated to investigate the impact of this arrangement on the heat transmission rate from the *** gotten results indicate that the rate of heat transmission increases with decreases in the longitudinal spacing(SL).As the longitudinal spacing(SL)increases to about 44%the Nusselt number is slightly decreased by about 9%.The coefficient of heat transmission,Nusselt number,and the heat transmission data obtained from(CFD)Compared to previous research results,there is a decent agreement originating after comparison.

关键词： Tube bundle numerical study longitudinal pitch cross-flow staggered

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Theoretical evaluation of dielectric materials for lightning energy harvesting system

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Clean Energy 2022年第6期6卷 869-878页

作者： saad Uddina Jinan Gua Muhammad Ajmal School of Mechanical Engineering Jiangsu UniversityZhenjiang 212013China School of Agricultural Equipment Engineering Jiangsu UniversityZhenjiang 212013China

This study describes the hypothetical approach to system design to collect and store electrical energy present in a flash of *** system’s operations include the attraction and handling of the electrical charge obtained from lightning *** differences arise from three different dielectric materials(rutile,mica and quartz)and the results define the estimated response of the storage system,including charge *** the results in this article were obtained through simulation or demonstrated mathematically showing the estimated outcomes of the *** findings demonstrate that each dielectric material has its own advantages and disadvantages that influence the efficiency of the storage *** analysing the distinction of the three materials,it is observed that mica is the most suitable dielectric material,as it has the greatest dielectric strength,which is the main factor in the handling of charge.

关键词： lightning energy capacitor design harvesting system renewable energy

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Artificial Intelligence Techniques Based Learner Authentication in Cybersecurity Higher Education Institutions

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Computers, Materials & Continua 2022年第8期72卷 3131-3144页

作者： Abdullah saad AL-Malaise AL-Ghamdi Mahmoud Ragab Information Systems Department Faculty of Computing and Information Technology King Abdulaziz UniversityJeddah21589Saudi Arabia Information Technology Department Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia Centre of Artificial Intelligence for Precision Medicines King Abdulaziz UniversityJeddah21589Saudi Arabia Mathematics Department Faculty of ScienceAl-Azhar UniversityNaser City11884CairoEgypt

Education 4.0 is being authorized more and more by the design of artificial intelligence(AI)*** education institutions(HEI)have started to utilize Internet technologies to improve the quality of the service and boost *** to the unavailability of information technology(IT)infrastructures,HEI is vulnerable to *** authentication can be used to authenticate a person based on biological features such as face,fingerprint,iris,and so *** study designs a novel search and rescue optimization with deep learning based learning authentication technique for cybersecurity in higher education institutions,named SRODLLAC *** proposed SRODL-LAC technique aims to authenticate the learner/student in HEI using fingerprint ***,the SRODLLACtechnique designs a median filtering(MF)based preprocessing approach to improving the quality of the *** addition,the Densely Connected Networks(DenseNet-77)model is applied for the extraction of ***,search and rescue optimization(SRO)algorithm with deep neural network(DNN)model is utilized for the classification ***,template matching process is done for fingerprint identification.A wide range of simulation analyses is carried out and the results are inspected under several *** experimental results reported the effective performance of the SRODL-LAC technique over the other methodologies.

关键词： Cybersecurity authentication biometrics security higher education institution deep learning

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Hydrogen FBG Sensor Using Pd/Ag Film With Application in Propulsion System Fuel Tank Model of Aerospace Vehicle

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Photonic Sensors 2014年第3期4卷 254-264页

作者： Said saad Lotfi HASSINE Vassim ELFAHEM Group of Electronics and Quantum Physics Laboratory of Advanced Materials and Quantum Phenomena Faculty ofSciences of Tunis 2092 Tunisia National Institute of Applied Sciences and Technology University of Carthage North Urban Center of Tunis-B.P. 676Cedex Tunis 1080 Tunisia Regio iT Gesellschaft mit beschrankter Hafiung Aachen Germany

The high efficiency hydrogen fiber Bragg grating （FBG） sensor is presented. The sensitive film was a new alliance of palladium-silver （Pd-Ag）. In addition, the titanium （Ti） layer was used as the adhesive layer. The presented sensor showed the resolution of more than 60pm/1%H2, and a fast response time of4s - 5s was guaranteed in the 0.1%H2 - 4%H2 range. Moreover, the life time of the sensor was investigated. The obtained results showed that the sensor had an enhanced life time. Furthermore, the sensor was applied in the propulsion system fuel tank model of the aerospace vehicle. The obtained results indicated that it is a prevention system against the disaster aerospace due to hydrogen leakage.

关键词： Hydrogen fiber Bragg grating palladium-silver faster response time propulsion system fuel tank prevention system hydrogen leakage

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Silicon mediated synthesis and selected transformations of β-chloroketones

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Chinese Chemical Letters 2011年第10期22卷 1171-1174页

作者： Tarek A.Salama saad S.Elmorsy Chemistry Department Faculty of ScienceMansoura University35516 MansouraEgypt Chemistry Department Faculty of EducationAmran UniversityAmranYemen

A combination of tetrachlorosilane（TCS） and phenol in dichloromethane was found to be an efficient reagent for hydro-chlorination ofα,β-unsaturated ketones to afford the correspondingβ-chloroketones in good yield at ambient temperature. Reactions of the titled compounds with TCS-NaN_3 as well as with nitriles utilizing TCS-ZnCl_2 to give 1,5-disubstituted tetrazole derivatives orβ-amido ketones respectively are also described.

关键词： Tetrachlorosilane Phenol β-Chloroketones Synthesis Tetrazoles β-Amido ketones

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Basics on the use of acid-sensing ion channels' inhibitors as therapeutics

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Neural Regeneration Research 2019年第3期14卷 395-398页

作者： Jamileh Dibas Houssam Al-saad Adnan Dibas Faculty of Pharmacy Applied UniversityAmman Jordan North Texas Eye Research Institute Department of Pharmacology and Neuroscience University of North Texas Health Science Center at Fort Worth

Since the discovery of acid-sensing ion channels in 1997, their importance in the health of neurons and other non-neuronal cells has gained significant importance. Acid-sensing ion channels play important roles in mediating pain sensation during diseases such as stroke, inflammation, arthritis, cancer, and recently migraine. More interestingly, acid-sensing ion channels may explain the sex differences in pain between males and females. Also, the ability of acid-sensing ion channel blockers to exert neuroprotective effects in a number of neurodegenerative diseases has added a new dimension to their therapeutic value. The current failure rate of ～45% of new drugs(due to toxicity issues) and saving of up to 7 years in the life span of drug approval makes drug repurposing a high priority. If acid-sensing ion channels' blockers undergo what is known as "drug repurposing", there is a great potential to bring them as medications with known safety profiles to new patient populations. However, the route of administration remains a big challenge due to their poor penetration of the blood brain and retinal barriers. In this review, the promise of using acid-sensing ion channel blockers as neuroprotective drugs is discussed.

关键词： optic nerve glaucoma neurodegeneration neuroprotection acid sensing ion channel calpain

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Assessing workability of greased bearings after long-term storage

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Friction 2019年第5期7卷 489-496页

作者： Michael VARENBERG Yuri KLIGERMAN Grigory HALPERIN saad NAKAD Haytam KASEM George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGA30332USA Department of Mechanical Engineering Technion-Israel Institute of TechnologyHaifa32000Israel Department of Mechanical Engineering Azrieli College of EngineeringJerusalem9103501Israel

Here, we developed a technique to assess the workability of sealed-for-life greased rolling bearings after a long-term storage. In this framework, we devised a model of equivalent transition between the conditions of natural ageing under daily and seasonally fluctuating temperature, and the conditions of accelerated thermal ageing at a constant high temperature. The tested bearings were thermally aged, and then their steady state friction and outer ring temperature were examined in a custom high-speed spindle. These results were compared to the performance of a reference new bearing tested under the same loading conditions. Our findings suggest that long-term storage can significantly degrade the performance of sealed-for-life greased rolling bearings. However, a proper running-in can substantially deter the ageing-driven degradation of the bearings.

关键词： grease lubrication ball bearings thermal ageing lubricant degradation

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Deep Learning Based Cyber Event Detection from Open-Source Re-Emerging Social Data

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Computers, Materials & Continua 2023年第8期76卷 1423-1438页

作者： Farah Mohammad saad Al-Ahmadi Jalal Al-Muhtadi Center of Excellence in Information Assurance(CoEIA) King Saud UniversityRiyadh11543Saudi Arabia College of Computer&Information Sciences King Saud UniversityRiyadh11543Saudi Arabia

Social media forums have emerged as the most popular form of communication in the modern technology era,allowing people to discuss and express their *** increases the amount of material being shared on social media *** is a wealth of information about the threat that may be found in such open data *** security of already-deployed software and systems relies heavily on the timely detection of newly-emerging threats to their safety that can be gleaned from such *** the fact that several models for detecting cybersecurity events have been presented,it remains challenging to extract security events from the vast amounts of unstructured text present in public data *** majority of the currently available methods concentrate on detecting events that have a high number of *** is because the unstructured text in open data sources typically contains a large number of ***,to react to attacks quicker than they can be launched,security analysts and information technology operators need to be aware of critical security events as soon as possible,regardless of how often they are *** research provides a unique event detection method that can swiftly identify significant security events from open forums such as *** proposed work identified new threats and the revival of an attack or related event,independent of the volume of mentions relating to those events on *** this research work,deep learning has been used to extract predictive features from open-source *** proposed model is composed of data collection,data transformation,feature extraction using deep learning,Latent Dirichlet Allocation(LDA)based medium-level cyber-event detection and final Google Trends-based high-level cyber-event *** proposed technique has been evaluated on numerous *** results show that the proposed method outperforms existing methods in detecting cyber events by giving 95.96

关键词： Social media twitter cyber events deep learning

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