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Evaluation of the influence of El Niño–Southern Oscillation on air quality in southern China from long-term

Frontiers of Environmental Science & Engineering 2022, Volume 16, Issue 2, doi: 10.1007/s11783-021-1460-0

Abstract:

•Strong ENSO influence on AOD is found in southern China region.

Keywords： El Niño–Southern Oscillation     Aerosol concentration     Aerosol particle size     Contribution separation    

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A novel hybrid cryptosystem based on DQFrFT watermarking and 3D-CLM encryption for healthcare services Research Article

Fatma KHALLAF, Walid EL-SHAFAI, El-Sayed M. EL-RABAIE, Naglaa F. SOLIMAN, Fathi E.Abd EL-SAMIE,fatma.mohammed333@gmail.com,eng.waled.elshafai@gmail.com,elsayedelrabaie@gmail.com,nfsoliman

Frontiers of Information Technology & Electronic Engineering 2023, Volume 24, Issue 7,   Pages 1045-1061 doi: 10.1631/FITEE.2200372

Abstract: algebra has been used to apply the fractional Fourier transform (FrFT) to color images in a comprehensive approach. However, the discrete fractional random transform (DFRNT) with adequate basic randomness remains to be examined. This paper presents a novel multistage privacy system for s based on discrete fractional Fourier transform (DQFrFT) watermarking and . First, we describe DFRNT (QDFRNT), which generalizes DFRNT to handle signals effectively, and then use QDFRNT to perform . To efficiently evaluate QDFRNT, this study derives the relationship between the QDFRNT of a signal and the four components of the DFRNT signal. Moreover, it uses the human vision system’s (HVS) masking qualities of edge, texture, and color tone immediately from the color host image to adaptively modify the watermark strength for each block in the using the QDFRNT-based and support vector machine (SVM) techniques. The limitations of watermark embedding are also explained to conserve watermarking energy. Second, 3D-CLM is employed to improve the system’s security and efficiency, allowing it to be used as a multistage privacy system. The proposed security system is effective against many types of channel noise attacks, according to simulation results.

Keywords： Color medical image     Quaternion     Adaptive watermarking     Encryption     Fractional transform     Three-dimensional chaotic logistic map (3D-CLM)    

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Hydrophobic polyethersulfone porous membranes for membrane distillation

Heba ABDALLAH, Ayman EL-GENDI, Maaly KHEDR, Elham EL-ZANATI

Frontiers of Chemical Science and Engineering 2015, Volume 9, Issue 1,   Pages 84-93 doi: 10.1007/s11705-015-1508-4

Abstract: Membrane distillation (MD) is a thermal, vapor-driven transportation process through micro porous hydrophobic membranes that is increasingly being applied to seawater and brine desalination processes. Two types of hydrophobic microporous polyethersulfone flat sheet membranes, namely, annealed polyethersulfone and a polyethersulfone/tetraethoxysilane (PES/TEOS) blend were prepared by a phase inversion process. The membranes were characterized and their performances were investigated using the vacuum membrane distillation of an aqueous NaCl solution. The performances of the prepared membranes were also compared with two commercially available hydrophobic membranes, polytetrafluorethylene and polyvinylidene fluoride. The influence of operational parameters such as feed temperature (25–65 °C), permeate vacuum pressure (200–800 mbar), feed flow rate (8–22 mL/s) and feed salt concentration (3000 to 35000 mg/L) on the MD permeation flux were investigated for the four membranes. The hydrophobic PES/TEOS membrane had the highest salt rejection (99.7%) and permeate flux (86 kg/m ·h) at 65 °C, with a feed of 7000 ppm and a pressure of 200 mbar.

Keywords： membrane distillation     hydrophobic membrane     salt rejection     permeate flux    

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In situ-based assessment of soil liquefaction potential–Case study of an earth dam in Tunisia

Ikram GUETTAYA,Mohamed Ridha EL OUNI

Frontiers of Structural and Civil Engineering 2014, Volume 8, Issue 4,   Pages 456-461 doi: 10.1007/s11709-014-0259-5

Abstract: The present paper examines the evaluation of liquefaction potential of an earth dam foundation in Tunisia. The assessment of soil liquefaction was made using deterministic and probabilistic simplified procedures developed from several case histories. The data collected from the field investigation performed before and after the vibrocompaction are analyzed and the results are reported. The obtained results show that after vibrocompaction, a significant improvement of the soil resistance reduces the liquefaction potential of the sandy foundation. Indeed, in the untreated layers, the factor of safety drops below 1 which means that the soil is susceptible for liquefaction. However, in the compacted horizons, the values of exceed the unit which justifies the absence of liquefaction hazard of the foundation.

Keywords： liquefaction     cone penetration test (CPT)     standard penetration test (SPT)     vibrcompaction     sand    

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Predicting resilient modulus of recycled concrete and clay masonry blends for pavement applications using soft computing techniques

EL-BADAWY, Ali ARISHA, Sayed SHWALLY, Jong WAN HU

Frontiers of Structural and Civil Engineering 2019, Volume 13, Issue 6,   Pages 1379-1392 doi: 10.1007/s11709-019-0562-2

Abstract: To date, very few researchers employed the Least Square Support Vector Machine (LSSVM) in predicting the resilient modulus ( ) of Unbound Granular Materials (UGMs). This paper focused on the development of a LSSVM model to predict the of recycled materials for pavement applications and comparison with other different models such as Regression, and Artificial Neural Network (ANN). Blends of Recycled Concrete Aggregate (RCA) with Recycled Clay Masonry (RCM) with proportions of 100/0, 90/10, 80/20, 70/30, 55/45, 40/60, 20/80, and 0/100 by the total aggregate mass were evaluated for use as UGMs. RCA/RCM materials were collected from dumps on the sides of roads around Mansoura city, Egypt. The investigated blends were evaluated experimentally by routine and advanced tests and the values were determined by Repeated Load Triaxial Test (RLTT). Regression, ANN, and LSSVM models were utilized and compared in predicting the of the investigated blends optimizing the best design model. Results showed that the ’s of the investigated RCA/RCM blends were generally increased with the decrease in RCM proportion. Statistical analyses were utilized for evaluating the performance of the developed models and the inputs sensitivity parameters. Eventually, the results approved that the LSSVM model can be used as a novel tool to estimate the of the investigated RCA/RCM blends.

Keywords： Least Square Support Vector Machine     Artificial Neural Network     resilient modulus     Recycled Concrete Aggregate     Recycled Clay Masonry    

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Wind-diesel hybrid power system integration in the south Algeria

Khaireddine ALLALI,El Bahi AZZAG,Nabil KAHOUL

Frontiers in Energy 2015, Volume 9, Issue 3,   Pages 259-271 doi: 10.1007/s11708-015-0367-5

Abstract: In most isolated sites situated in south Algeria, the diesel generators are the major source of electrical energy. Indeed, the power supply of these remote regions still poses order problems (technical, economical and ecological). The electricity produced with the help of diesel generators is very expensive and responsible for CO emission. These isolated sites have significant wind energy potential. Hence, the use of twinning wind-diesel is widely recommended, especially to reduce operating deficits. The objective of this paper is to study the global modeling of a hybrid system which compounds wind turbine generator, diesel generator and storage system. This model is based on the control strategy to optimize the functioning of the hybrid system and to consolidate the gains to provide proper management of energy sources (wind, diesel, battery) depending on the load curve of the proposed site. The management is controlled by a controller which ensures the opening/closing of different power switches according to meteorological conditions (wind speed, air mass, temperature, etc).

Keywords： wind-diesel     storage system     isolated site     management     simulation    

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Bioreduction of nitrate in groundwater using a pilot-scale hydrogen-based membrane biofilm reactor

Youneng TANG, Michal ZIV-EL, Chen ZHOU, Jung Hun SHIN, Chang Hoon AHN, Bruce E.

Frontiers of Environmental Science & Engineering 2010, Volume 4, Issue 3,   Pages 280-285 doi: 10.1007/s11783-010-0235-9

Abstract: A long-term pilot-scale H-based membrane biofilm reactor (MBfR) was tested for removal of nitrate from actual groundwater. A key feature of this second-generation pilot MBfR is that it employed lower cost polyester hollow fibers and still achieved high loading rate. The steady-state maximum nitrate surface loading at which the effluent nitrate and nitrite concentrations were below the Maximum Contaminant Level (MCL) was at least 5.9 g·N·(m·d), which corresponds to a maximum volumetric loading of at least 7.7 kg·N·(m·d) . The steady-state maximum nitrate surface area loading was higher than the highest nitrate surface loading reported in the first-generation MBfRs using composite fibers (2.6 g·N·(m·d)). This work also evaluated the H-utilization efficiency in MBfR. The measured H supply rate was only slightly higher than the stoichiometric H-utilization rate. Thus, H utilization was controlled by diffusion and was close to 100% efficiency, as long as biofilm accumulated on the polyester-fiber surface and the fibers had no leaks.

Keywords： denitrification     groundwater treatment     hydrogen     membrane biofilm reactor (MBfR)     polyester fiber    

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Oxidative leaching kinetics of molybdenum-uranium ore in H

El-Ahmady, H. B. Hassib, A. S. Helal

Frontiers of Chemical Science and Engineering 2013, Volume 7, Issue 1,   Pages 95-102 doi: 10.1007/s11705-013-1317-6

Abstract: The processing of molybdenum-uranium ore in a sulfuric acid solution using hydrogen peroxide as an oxidant has been investigated. The leaching temperature, hydrogen peroxide concentration, sulfuric acid concentration, leaching time, particle size, liquid-to-solid ratio and agitation speed all have significant effects on the process. The optimum process operating parameters were: temperature: 95°C; H O concentration: 0.5 M; sulfuric acid concentration: 2.5 M; time: 2 h; particle size: 74 μm, liquid-to-solid ratio: 14 ∶ 1 and agitation speed: 600 rpm. Under these experimental conditions, the extraction efficiency of molybdenum was about 98.4%, and the uranium extraction efficiency was about 98.7%. The leaching kinetics of molybdenum showed that the reaction rate of the leaching process is controlled by the chemical reaction at the particle surface. The leaching process follows the kinetic model 1 ? (1? ) = with an apparent activation energy of 40.40 kJ/mole. The temperature, concentrations of H O and H SO and the mesh size are the main factors that influence the leaching rate. The reaction order in H SO was 1.0012 and in H O it was 1.2544.

Keywords： leaching of molybdenum     leaching of uranium     kinetics    

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3D finite element analysis of composite noise barrier constructed of polyurethane products

Ben DAEE,Hesham El NAGGAR

Frontiers of Structural and Civil Engineering 2017, Volume 11, Issue 1,   Pages 100-110 doi: 10.1007/s11709-016-0364-8

Abstract: This paper presents a numerical investigation on the structural performance of an innovative noise barrier consisting of poly-block, rigid polyurethane foam (RPF) and polyurea. The mechanical characteristics of RPF as well as the flexural resistance of the proposed wall system (poly-wall) were established and presented in another study. The experimental results are used in the current study to develop, calibrate and verify 3D finite element (FE) models of the wall system. The components of the poly-wall including steel rebars, poly-blocks and RPF cores were simulated and then verified using the results of experiments conducted on the wall components. The results of numerical analysis exhibited a satisfactory agreement with the experimental outcomes for the entire wall system. The verified numerical models were then used to conduct a parametric study on the performance of poly-wall models under uniform wind load and gravity load. The findings of the current study confirmed that the structural performance of poly-wall is satisfactory for noise barrier application. Simulation techniques for improvement of the numerical analysis of multi-martial 3D FE models were discussed.

Keywords： 3D finite element     sound wall     rigid polyurethane foam     poly-wall     numerical model     calibration    

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The development of ultralightweight expanded perlite-based thermal insulation panel using alkali activator solution

Damla Nur ÇELİK; Gökhan DURMUŞ

Frontiers of Structural and Civil Engineering 2022, Volume 16, Issue 11,   Pages 1486-1499 doi: 10.1007/s11709-022-0881-6

Abstract: The International Energy Agency (IEA) states that global energy consumption will increase by 53% by 2030. Turkey has 70% of the world’s perlite reserves, and in order to reduce energy consumption a thermal insulation panel was developed in Turkey using different particle sizes of expanded perlite (EP). In this study, 0–1.18 mm (powder) and 0–3 mm (granular) EP particle sizes were selected, since they have the lowest thermal conductivity coefficients among all the particle sizes. In addition, an alkali activator solution was used as a binder in the mixtures. The alkaline activator solution was obtained by mixing sodium hydroxide solution (6, 8, 10, and 12 mol·L−1) and sodium silicate (Module 3) at the different ratios of Na2SiO3 to NaOH of 1, 1.5, 2, and 2.5. This study aimed to experimentally determine the optimum binder and distribution ratio of EP, with the lowest coefficient of thermal conductivity and the lowest density. The lowest thermal conductivity and the lowest density were determined as 0.04919 W·m−1·K−1 and 133.267 kg/m3, respectively, in the sample prepared with 83.33% powder-size EP, 6 mol·L−1 sodium hydroxide solution, and ratio of Na2SiO3 to NaOH of 1.5. The density, thermal conductivity, and compressive strength of the sample showed the same trends of behavior when the Na2SiO3 to NaOH ratio was increased. In addition, the highest compressive strength was measured in 12 mol·L−1 NaOH concentration regardless of particle size. In conclusion, the study predicts that the EP-based thermal insulation panel can be used as an insulation material in the construction industry according to the TS825 Thermal Insulation Standard.

Keywords： expanded perlite     alkali activator     thermal insulation panel     thermal conductivity    

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A DNA sensor based on upconversion nanoparticles and two-dimensional dichalcogenide materials

El-Sagheer, Tom Brown, Otto L. Muskens, Antonios G. Kanaras

Frontiers of Chemical Science and Engineering 2021, Volume 15, Issue 4,   Pages 935-943 doi: 10.1007/s11705-020-2023-9

Abstract: We demonstrate the fabrication of a new DNA sensor that is based on the optical interactions occurring between oligonucleotide-coated NaYF : Yb ; Er upconversion nanoparticles and the two-dimensional dichalcogenide materials, MoS and WS . Monodisperse upconversion nanoparticles were functionalized with single-stranded DNA endowing the nanoparticles with the ability to interact with the surface of the two-dimensional materials via van der Waals interactions leading to subsequent quenching of the upconversion fluorescence. By contrast, in the presence of a complementary oligonucleotide target and the formation of double-stranded DNA, the upconversion nanoparticles could not interact with MoS and WS , thus retaining their inherent fluorescence properties. Utilizing this sensor we were able to detect target oligonucleotides with high sensitivity and specificity whilst reaching a concentration detection limit as low as 5 fmol·L , within minutes.

Keywords： upconversion nanoparticles     DNA sensor     two-dimensional materials     MoS2     WS2    

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The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

Frontiers of Chemical Science and Engineering 2022, Volume 16, Issue 3,   Pages 397-407 doi: 10.1007/s11705-021-2076-4

Abstract: Herein, a series of Ni-doped PtSn catalysts were prepared, characterized and studied in the hydrogenationThe Ni dopant has a strong interaction with Pt, which promotes the hydrogen adsorption, providing anMeanwhile, the presence of Ni also improves the Pt dispersion, giving more accessible active sites forThe cooperation of Pt and Ni significantly promotes the catalytic activity of the hydrogenation of aceticAs a result, the catalyst with 0.1% Ni exhibits the best reaction activity, and its space time yield

Keywords： acetic acid     ethanol     hydrogenation     Pt     Ni     cooperation effect    

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Experimental investigation and comparative study of inter-turn short-circuits and unbalanced voltage supply in induction machines

Fatima BABAA, Abdelmalek KHEZZAR, Mohamed el kamel OUMAAMAR

Frontiers in Energy 2013, Volume 7, Issue 3,   Pages 271-278 doi: 10.1007/s11708-013-0258-6

Abstract: A transient model for an induction machine with stator winding turn faults on a single phase is derived using reference frame transformation theory. The negative sequence component and the 3rd harmonic are often considered as accurate indicators. However, small unbalance in the supply voltage and/or in the machine structure that exists in any real system engenders the same harmonics components. In this case, it is too difficult to distinguish between the current harmonics due to the supply voltage and those originated by inter-turn short-circuit faults. For that, to have the correct diagnosis and to increase the sensitivity and the reliability of the diagnostic system, it is crucial to provide the relationship between the inter-turn short-circuits in the stator winding and the supply voltage imbalance through an accurate mathematical model and via a series of experimental essays.

Keywords： induction machines     fault indicator     inter-turn short-circuit fault     unbalance supply voltage    

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Novel power capture optimization based sensorless maximum power point tracking strategy and internal model controller for wind turbines systems driven SCIG

Ali EL YAAKOUBI,Kamal ATTARI,Adel ASSELMAN,Abdelouahed DJEBLI

Frontiers in Energy 2019, Volume 13, Issue 4,   Pages 742-756 doi: 10.1007/s11708-017-0462-x

Abstract: Under the trends to using renewable energy sources as alternatives to the traditional ones, it is important to contribute to the fast growing development of these sources by using powerful soft computing methods. In this context, this paper introduces a novel structure to optimize and control the energy produced from a variable speed wind turbine which is based on a squirrel cage induction generator (SCIG) and connected to the grid. The optimization strategy of the harvested power from the wind is realized by a maximum power point tracking (MPPT) algorithm based on fuzzy logic, and the control strategy of the generator is implemented by means of an internal model (IM) controller. Three IM controllers are incorporated in the vector control technique, as an alternative to the proportional integral (PI) controller, to implement the proposed optimization strategy. The MPPT in conjunction with the IM controller is proposed as an alternative to the traditional tip speed ratio (TSR) technique, to avoid any disturbance such as wind speed measurement and wind turbine (WT) characteristic uncertainties. Based on the simulation results of a six KW-WECS model in Matlab/Simulink, the presented control system topology is reliable and keeps the system operation around the desired response.

Keywords： power optimization     wind energy conversion system     maximum power point tracking (MPPT)     fuzzy logic     internal model (IM) controller    

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Catalytic hydrolysis of gaseous HCN over Cu–Ni/γ-Al

Linxia Yan, Senlin Tian, Jian Zhou, Xin Yuan

Frontiers of Environmental Science & Engineering 2016, Volume 10, Issue 6, doi: 10.1007/s11783-016-0872-8

Abstract: The Cu–Ni/γ-Al O catalyst was prepared to study HCN hydrolysis ?decompose efficiently hydrogen cyanide (HCN) in exhaust gas, g-Al O -supported bimetallic-based Cu–Nivolume ratio, reaction temperature, and the presence of CO or O on the HCN removal efficiency on the Cu–Ni

Keywords： Hydrogen cyanide     Cu–Ni/g-Al2O3     Catalytic hydrolysis    

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Title Author Date Type Operation

Evaluation of the influence of El Niño–Southern Oscillation on air quality in southern China from long-term

Journal Article

A novel hybrid cryptosystem based on DQFrFT watermarking and 3D-CLM encryption for healthcare services

Fatma KHALLAF, Walid EL-SHAFAI, El-Sayed M. EL-RABAIE, Naglaa F. SOLIMAN, Fathi E.Abd EL-SAMIE,fatma.mohammed333@gmail.com,eng.waled.elshafai@gmail.com,elsayedelrabaie@gmail.com,nfsoliman

Journal Article

Hydrophobic polyethersulfone porous membranes for membrane distillation

Heba ABDALLAH, Ayman EL-GENDI, Maaly KHEDR, Elham EL-ZANATI

Journal Article

In situ-based assessment of soil liquefaction potential–Case study of an earth dam in Tunisia

Ikram GUETTAYA,Mohamed Ridha EL OUNI

Journal Article

Predicting resilient modulus of recycled concrete and clay masonry blends for pavement applications using soft computing techniques

EL-BADAWY, Ali ARISHA, Sayed SHWALLY, Jong WAN HU

Journal Article

Wind-diesel hybrid power system integration in the south Algeria

Khaireddine ALLALI,El Bahi AZZAG,Nabil KAHOUL

Journal Article

Bioreduction of nitrate in groundwater using a pilot-scale hydrogen-based membrane biofilm reactor

Youneng TANG, Michal ZIV-EL, Chen ZHOU, Jung Hun SHIN, Chang Hoon AHN, Bruce E.

Journal Article

Oxidative leaching kinetics of molybdenum-uranium ore in H

El-Ahmady, H. B. Hassib, A. S. Helal

Journal Article

3D finite element analysis of composite noise barrier constructed of polyurethane products

Ben DAEE,Hesham El NAGGAR

Journal Article

The development of ultralightweight expanded perlite-based thermal insulation panel using alkali activator solution

Damla Nur ÇELİK; Gökhan DURMUŞ

Journal Article

A DNA sensor based on upconversion nanoparticles and two-dimensional dichalcogenide materials

El-Sagheer, Tom Brown, Otto L. Muskens, Antonios G. Kanaras

Journal Article

The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

Journal Article

Experimental investigation and comparative study of inter-turn short-circuits and unbalanced voltage supply in induction machines

Fatima BABAA, Abdelmalek KHEZZAR, Mohamed el kamel OUMAAMAR

Journal Article

Novel power capture optimization based sensorless maximum power point tracking strategy and internal model controller for wind turbines systems driven SCIG

Ali EL YAAKOUBI,Kamal ATTARI,Adel ASSELMAN,Abdelouahed DJEBLI

Journal Article

Catalytic hydrolysis of gaseous HCN over Cu–Ni/γ-Al

Linxia Yan, Senlin Tian, Jian Zhou, Xin Yuan

Journal Article