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Hydraulic and volume change behaviors of compacted highly expansive soil under cyclic wetting and drying

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第2期15卷 486-499页

作者： Mohamed farid Abbas Abdullah Ali Shaker Mosleh A.Al-Shamrani Civil Engineering Department College of EngineeringPrince Sattam bin Abdulaziz UniversityAl KharjSaudi Arabia Soil Mechanics and Geotechnical Engineering Research Institute Housing and Building National Research Center(HBRC)GizaEgypt Bugshan Research Chair in Expansive Soils Civil Engineering DepartmentCollege of EngineeringKing Saud UniversityRiyadhSaudi Arabia

The wide engineered application of compacted expansive soils necessitates understanding their behavior under field *** results of this study demonstrate how seasonal climatic variation and stress and boundary conditions individually or collectively influence the hydraulic and volume change behavior of compacted highly expansive *** cyclic wetting and drying(CWD)process was applied for two boundary conditions,*** stress(CS)and constant volume(CV),and for a wide range of axial stress *** adopted CWD process affected the hydraulic and volume change behaviors of expansive soils,with the first cycle of wetting and drying being the most *** CWD process under CS conditions resulted in shrinkage accumulation and reduction in saturated hydraulic conductivity(k sat).On the other hand,CWD under CV conditions caused a reduction of swell pressure while has almost no impact on k *** elastic response to CWD was achieved after the third cycle for saturated hydraulic conductivity(k sat),the third to fourth cycle for the volume change potential under the CV conditions,and the fourth to fifth cycle for the volume change potential under the CS ***,both swell pressure(s s)and saturated hydraulic conductivity(k sat)are not fundamental parameters of the expansive soil but rather depend on stress,boundary and wetting conditions.

关键词： Expansive soils Hydraulic conductivity Volume change potential Cyclic wetting and drying(CWD) Swell pressure

A comparative study of a direct and pulse electrodeposition method of TiO_(2)films and its effect on photoelectrocatalytic degradation of methyl orange dye

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Optoelectronics Letters 2021年第6期17卷 334-341页

作者： Khadidja Hadj Larbi farid Habelhames Meriem Lakhdari farid Bennabi Belkacem Nessark Mehdi Adjdir Abdelkader Echchergui Nebatti Bouhalouane Amrani Laboratoire d'électrochimie et matériaux(LEM) Facultéde TechnologieDépartement de génie des procédésUniversitéFerhat Abbas Sétif-1Sétif19000Algérie Laboratory of Applied Chemistry University ofAin-Temouchent Belhadj BouchaibAlgeria Laboratory of Applied Organic Synthesis Faculty of Exact and Applied SciencesUniversity Oran1 Ahmed Ben BellaBP 1524 El M'NaouerOran 31000Algeria Laboratory of Materials Sciences and Applications(LMSA) University of Ain-Temouchent Belhadj BouchaibAlgeria Electron Microscopy Center Faculty of Exact and Applied SciencesUniversity of Oran1 Ahmed Ben BellaOranAlgeria

The present study reports the titanium dioxide(TiO_(2))films synthesized from TiCl3 precursor on ITO glass substrates using two electrochemical techniques,namely direct electro-deposition(DE)and pulse electro-deposition(PE).The synthesis potential during the time-on(Ton)period was fixed at-1.5 ***,the open-circuit potential was applied during the time-off(Toff)*** effect of the technique of electro-deposition and Toff duration on the properties of TiO_(2)films and their photoelectron-catalytic activity were *** obtained films were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-VIS spectrometer,and photocurrent measurement *** is found that the use of the PE technique at different Toff improves the properties of TiO_(2)films compared to the DE *** XRD patterns show the anatase phase with a marked preferential orientation along the(101)direction for all *** the SEM analysis,it is seen a significant change from big multigrain agglomerates at DE to a dense film structure and small multigrain agglomerates at different *** the Toff decreases from 3 s to 1 s,the photocurrent response rises and reaches a high value of about 12 m A/cm^(2).Compared with DE,and under UV light the photocatalytic property of TiO_(2)film synthesis via PE has been improved in the degradation of methyl orange(MO).Finally,the films deposited at low Toff(Toff=1 s)show a faster degradation of MO.

关键词： films orange effect

Comprehensive evaluation of machine learning algorithms applied to TBM performance prediction

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Underground Space 2022年第1期7卷 37-49页

作者： Jie Yang Saffet Yagiz Ying-Jing Liu farid Laouafa Zhongtian Construction Group Co.Ltd HangzhouChina Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina School of Mining and Geosciences Nazarbayev UniversityNur-Sultan 010000Kazakhstan National Institute for Industrial Environment and Risks(INERIS) Verneuil-en-HalatteFrance

To date,the accurate prediction of tunnel boring machine(TBM)performance remains a considerable challenge owing to the complex interactions between the TBM and *** evolutionary polynomial regression(EPR)and random forest(RF),this study devel-ops two novel prediction models for TBM *** models can predict the TBM penetration rate and field penetration index as outputs with four input parameters:the uniaxial compressive strength,intact rock brittleness index,distance between planes of weakness,and angle between the tunnel axis and planes of weakness(a).First,the performances of both EPR-and RF-based models are examined by comparison with the conventional numerical regression method(i.e.,multivariate linear regression).Subsequently,the performances of the RF-and EPR-based models are further investigated and compared,including the model robustness for unknown datasets,interior relationships between input and output parameters,and variable *** results indicate that the RF-based model has greater prediction accuracy,particularly in identifying outliers,whereas the EPR-based model is more convenient to use by field engineers owing to its explicit *** EPR-and RF-based models can accurately identify the relationships between the input and output *** ensures their excellent generalization ability and high prediction accuracy on unknown datasets.

关键词： Tunnel boring machine Evolutionary polynomial regression Random forest Optimization Regularization

FE modeling of concrete beams and columns reinforced with FRP composites

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Defence Technology（防务技术） 2021年第1期17卷 1-14页

作者： farid Abed Chahmi Oucif Yousef Awera Haya H.Mhanna Hakem Alkhraisha Department of Civil Engineering American University of SharjahP.O.Box 26666United Arab Emirates Institute of Structural Mechanics(ISM) Bauhaus-Universitat WeimarMarienstraße 15D-99423WeimarGermany

Compression and flexure members such as columns and beams are critical in a structure as its failure could lead to the collapse of the *** the present work,numerical analysis of square and circle short columns,and reinforced concrete(RC)beams reinforced with fiber reinforced polymer composites are carried *** work is divided into two *** the first part,numerical study of axial behavior of square and circular concrete columns reinforced with Glass Fiber Reinforced Polymer(GFRP)and Basalt Fiber Reinforced Polymer(BFRP)bars and spiral,and Carbon Fiber Reinforced Polymer(CFRP)wraps is *** results of the first part showed that the axial capacity of the circular RC columns reinforced with GFRP increases with the increase of the longitudinal reinforcement *** addition,the results of the numerical analysis showed good correlation with the experimental *** interaction diagram for BFRP RC columns is also developed with considering various *** results of numerical modeling of RC columns strengthened with CFRP wraps revealed that the number and the spacing between the CFRP wraps provide different levels of ductility enhancement to the *** the cases considered in this study,column with two middle closely spaced CFRP wraps demonstrated the best *** the second part of this research,flexural behavior of RC beams reinforced with BFRP,GFRP and CFRP bars is investigated along with validation of the numerical model with the experimental *** results resembled the experimental observations that indicate significant effect of the FRP bar diameter and type ont he flexural capacity of the RC *** was also shown that Increasing the number of bars while keeping the same reinforcement ratio enhanced the stiffness of the RC beam.

关键词： Numerical analysis BRFP GFRP CFRP Columns Beams Experimental tests

Nexus between foreign direct investment and economic growth in Bangladesh: an augmented autoregressive distributed lag bounds testing approach

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Financial Innovation 2020年第1期6卷 173-190页

作者： Bibhuti Sarker farid Khan Department of Economics University of ManitobaWinnipegManitobaCanada Department of Economics Bangabandhu Sheikh Mujibur Rahman Science and Technology UniversityGopalganj 8100Bangladesh Department of Economics Rajshahi UniversityRajshahi 6205Bangladesh

The relationship between foreign direct investment(FDI)inflows and economic growth in host countries is a heavily debated *** some studies have found evidence of the positive impact of FDI on economic growth,others have revealed the opposite *** that examined the causality between FDI and gross domestic product(GDP)also have found evidence of unidirectional causality and,in some cases,a bidirectional *** study investigated the causal nexus between FDI and GDP in Bangladesh by employing standard time-series econometric tools,namely,augmented Dickey-Fuller,augmented Dickey-Fuller generalized least square,Kwiatkowski-Phillips-Schmidt-Shin,and Lee-Strazicich unit root tests to check stationarity,augmented autoregressive distributed lag(augmented ARDL)bounds testing approach to check cointegration,and Granger causality to explore the direction of *** augmented ARDL model found a long-run relationship between FDI and *** addition,the error correction model and Granger causality results indicated the presence of a unidirectional causality running from GDP to FDI.

关键词： FDI GDP Augmented ARDL Causality Economic growth

Statistical Shallow Water Acoustic Channel Modelling and BER Performance Investigation of CI-OFDM

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Statistical Shallow Water Acoustic Channel Modelling and BER...

作者： SALMAN farid 华南理工大学

学位级别：硕士

Underwater Acoustic（UWA）Communication uses acoustic waves to transmit and receive data under the *** radio waves suffer from high *** waves suffer from heavy *** waves are a better communication mode for underwater *** communication is challenging due to impairments,including attenuation,multipath propagation,noise and Doppler *** channels are one of the most stimulating communication *** varying multipath fading,long delay spread,significant Doppler spread,and frequency-dependent path loss are the focal characteristics of such *** channel measurement is obtained through experiments which are very costly and restricted to definite settings such as water depth,transceiver distance transceiver depth,and relative *** order to design and analyze UWA channels,computer simulations give us enhanced degrees of freedom to efficiently simulate and analyze UWA *** thesis presents a statistical shallow water channel model for moving transmitter and receiver based on analytical *** do so,a model of Shallow Water Acoustic（SWA）Channel Impulse Response（CIR）is derived first to capture most of the physical properties of shallow *** we find the Angle of Arrival（AoA）for paths with different numbers of surface and bottom reflections and the Probability Density Function（PDF）of（AoA）.To find closed form expressions for the statistics of the CIR,we approximate the PDFs of AoA with half-circular Rician *** mathematical controllability of this new PDF,analytical statistics including autocorrelation function and scattering function are *** and high data rate UWA communications are hard to achieve because of multipath propagation,frequency selective fading and limited *** is an appealing technique for UWA communication with three obvious advantages: good performance against frequency multipath interference,ability to combat the frequency selective fadin

关键词：水声信道正交频分复用误码性能

Status of Cadmium Concentration in Soil and Vegetable Irrigated with City Effluent

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应用与环境生物学报 2006年第3期12卷 414-419页

作者： farid Sajid BALOCH Musa Kaleem AKHTAR Kanwar Saleem Department of Chemistry Gomal UniversityDera Ismail KhanPakistan Department of Chemical Engineering NFC Institute of Engineering and Fertilizer ResearchFaisalabadPakistan

Cadmium(Cd) is a toxic and carcinogenic element,and it causes different diseases for people like sever nausea,salivation vomiting,diarrhoea,abdominal pain and neuralgia when it comes into food chain at excessive *** is also not included in the micronutrients for plant *** to arid and semi arid conditions of Pakistan,rainfall is small,causing shortage of irrigation *** of this shortage,farmers largely use city effluents for raising vegetables in the areas around big cities,which are contaminated with industrial *** effluents from Pakistan third largest city(Faisalabad) are used as supplementary irrigation water to produce vegetables for human *** paper reports a study on assessment of risks and opportunities associated with this practice,with emphasis on Cd,which can enter the food chain as an impurity in *** and other elements were measured in some typical effluents,four types of soils and many vegetables with no fertilizer *** was found that the municipal effluents increased soil salinity,sodicity and Cd *** Cd concentration in the vegetables was high above those normally associated with suitability for human *** were suggestions that soluble Cd concentration in the effluents could be lessened by adding lime,concurrently lowering the sodium adsorption ratio and residual sodium carbonate of the effluents,thus making them safe for utilization on agricultural soils.(Fig 1),Tab 7,Ref

关键词：镉耕种土壤蔬菜城市污水费萨那巴德巴基斯坦

Microstructure Evolution and Pore Formation Mechanism of Porous TiAl3 Intermetallics via Reactive Sintering

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Acta Metallurgica Sinica(English Letters) 2018年第4期31卷 440-448页

作者： Xinyang Jiao Xiaohong Wang Peizhong Feng Yanan Liu Laiqi Zhang farid Akhtar School of Materials Science and Engineering China University of Mining and TechnologyXuzhou 221116People's Republic of China School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116People's Republic of China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing100083People's Republic of China Division of Materials Science Lulefi University of Technology97187 LulJtSweden

Porous TiAl3 intermetallics were fabricated through vacuum reactive sintering from Ti-75A1 at.% elemental powder *** phase compositions,expansion behaviors,pore characteristics and microstructure evolution of TiAl3 intermetallics were investigated,and the pore formation mechanism was also *** was found that the actual temperature of compacts showed an acute climb from 668 to 1244℃ in 166s,while the furnace temperature maintained the linear growth of 5℃/min,which indicated that an obvious thermal explosion（TE）reaction occurred during sintering,and only single-phase TiA13 intermetallic was synthesized in TE *** open porosity increased from 22.2（green compact）to 32.8% after reactive diffusion sintering at 600℃ and rised to 58.7% after TE,then decreased to 51.2% after high-temperature homogenization at 1100℃.Therefore,TE reaction is the dominated pore formation mechanism of porous TiAl3 *** pore evolution in porous TiAl3 intermetallics occurred by the following mechanisms：certain intergranular pores remained among powder particles of green compact,then low-temperature sintering resulted in a further increase in porosity due to the Kirkendall ***,TE reaction gave rise to a dramatic volume expansion because of the rapid increase in temperature,and high-temperature sintering caused densification and a slight shrinkage.

关键词： Intermetallics Porous materials Powder metallurgy Reaction synthesis Thermal explosionsynthesis

Influence of heat treatment on fracture and magnetic properties of radially oriented Sm_2Co_(17) permanent magnets

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中国有色金属学会会刊：英文版 2007年第3期17卷 491-495页

作者：田建军曲选辉张深根 A. farid 陶斯武杜学丽 School of Materials Science and Engineering University of Science and Technology Beijing

The quenching, fracture and aging treatment of radially oriented Sm_2Co_(17) ring magnets were investigated. The results indicate that the ring magnets have obvious anisotropy of thermal expansion, which easily leads to the splits of the magnets during quenching. The fracture is brittle cleavage fracture. The difference (?a) of the expansion coefficient reaches the maximum value at 800-850 ℃. So, various quenching processes at different steps are adopted in order to reduce the splits. When the magnets are aged, 1:5 phase precipitates from the 2:17 matrix phase and forms a cellular microstructure with 2:17 phase. BHmax and JHc reach the maximum value 226 kJ/m3 and 2 170 kA/m after being aged at 850 ℃ for 4 h and 8 h, respectively. The aging treatment at 850 ℃ has little influence on remanence(Br), which can always keep a high value (≥1.0 T). Through appropriate heat treatment, the ring magnets have uniform cellular microstructure and excellent magnetic properties: Br≥1.0T, JHc≥2 100 kA/m, BHmax≥220 kJ/m3.

关键词：热处理电磁铁放射元素金属断口