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Isothermal, kinetic, and thermodynamic studies for solid-phase extraction of uranium(vi) via hydrazine-impregnated carbonbased material as efficient adsorbent

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Nuclear Science and Techniques 2019年第11期30卷 41-51页

作者： A.Morsy M.h.Taha Muhammad Saeed amir Waseem Muhammad Asad Riaz M.M.Elmaadawy Nuclear Materials Authority El MaddiP.O.Box 530CairoEgypt Department of Chemistry Quaid-i-Azam UniversityIslamabad 45320Pakistan

The current study describes the application of a new extraction method for efficient uranium adsorption via cost-effective hydrazine-impregnated activated *** experimental parameters such as time, adsorbent weight, temperature(°C), and uranium concentration were thoroughly investigated. The synthesized adsorbent was characterized via X-ray diffraction, Fourier transformation infrared spectroscopy(FT-IR), scanning electron microscopy, and thermogravimetric analysis. The results showed86% uranium extraction under optimized conditions(20% P2O5 at 25 °C, 120 min). The obtained findings fit well with thermodynamic and isothermal(Langmuir and Freundlich isotherms) models and pseudo second-order kinetics. In thermodynamic studies, the negative sign of(DG°) specified the spontaneity of process, the negative sign of(Dh°) revealed endothermicity, and the positive sign of(DS°) showed high randomness after adsorption.

关键词： Uranium Adsorption Phosphoric acid hydrazine Carbon

Genomic Prediction of Arsenic Tolerance and Grain Yield in Rice: Contribution of Trait-Specific Markers and Multi-Environment Models

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Rice science 2021年第3期28卷 268-278页

作者： Nourollah AhMADI Tuong-vi CAO Julien FROUIN Gareth J.NORTON Adam h.PRICE Institute of Genetic Improvement and Adaptation of Mediterranean and Tropical Plants French Agricultural Research and International Cooperation OrganizationMontpellier F-34398France University of Montpellier National Research Institute for AgricultureFood and EnvironmentFrench Agricultural Research and International Cooperation OrganizationMontpellier SupAgroMontpellier 34090France School of Biological Sciences University of AberdeenAberdeen AB243UUScotland

Many rice-growing areas are affected by high concentrations of arsenic(As).Rice varieties that prevent As uptake and/or accumulation can mitigate As threats to human *** selection is known to facilitate rapid selection of superior genotypes for complex *** explored the predictive ability(PA)of genomic prediction with single-environment models,accounting or not for trait-specific markers,multi-environment models,and multi-trait and multi-environment models,using the genotypic(1600K SNPs)and phenotypic(grain As content,grain yield and days to flowering)data of the Bengal and Assam Aus *** the base-line single-environment model,PA of up to 0.707 and 0.654 was obtained for grain yield and grain As content,respectively;the three prediction methods(Bayesian Lasso,genomic best linear unbiased prediction and reproducing kernel hilbert spaces)were considered to perform similarly,and marker selection based on linkage disequilibrium allowed to reduce the number of SNP to 17K,without negative effect on PA of genomic ***-environment models giving distinct weight to trait-specific markers in the genomic relationship matrix outperformed the base-line models up to 32%.Multi-environment models,accounting for genotype×environment interactions,and multi-trait and multi-environment models outperformed the base-line models by up to 47%and 61%,*** the multi-trait and multi-environment models,the Bayesian multi-output regressor stacking function obtained the highest predictive ability(0.831 for grain As)with much higher efficiency for computing *** findings pave the way for breeding for As-tolerance in the progenies of biparental crosses involving members of the Bengal and Assam Aus *** prediction can also be applied to breeding for other complex traits under multiple environments.

关键词： genomic prediction model genomic selection complex trait arsenic tolerance rice predictive ability

Functional relationship between ammonia-oxidizing bacteria and ammonia-oxidizing archaea populations in the secondary treatment system of a full-scale municipal wastewater treatment plant

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Journal of Environmental Sciences 2019年第12期31卷 120-130页

作者： Golam MIslam Peter vi Kimberley Ann Gilbride Department of Chemistry and Biology Ryerson University350 Victoria StreetTorontoOntario M5B 2K3Canada Ryerson Urban Water Ryerson University350 Victoria StreetTorontoOntario M5B 2K3Canada

The abundance of ammonia-oxidizing bacteria and archaea and their amo A genes from the aerobic activated sludge tanks,recycled sludge and anaerobic digesters of a full-scale wastewater treatment plant(WWTP)was *** chain reaction and denaturing gradient gel electrophoresis were used to generate diversity profiles,which showed that each population had a consistent profile although the abundance of individual members *** the aerobic tanks,the ammonia-oxidizing bacterial(AOB)population was more than 350 times more abundant than the ammonia-oxidizing archaeal(AOA)population,however in the digesters,the AOA population was more than 10 times more *** the activity of the amo A gene expression of the two populations using RT-PCR also showed that the AOA amo A gene was more active in the digesters than in the activated sludge *** batch reactors and dd PCR,amo A activity could be measured and it was found that when the AOB amo A activity was inhibited in the anoxic reactors,the expression of the AOA amo A gene increased *** suggests that these two populations may have a cooperative relationship for the oxidation of ammonia.

关键词： Wastewater treatment Topic:Ammonia-oxidation Ammonia-oxidizing bacteria(AOB) Ammonia-oxidizing archaea(AOA) PCR Digital droplet polymerase chain reaction(ddPCR)

Microscopic theory of light-induced ultrafast skyrmion excitation in transition metal films

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npj Computational Materials 2022年第1期8卷 598-604页

作者： Emil viñas Boström Angel Rubio Claudio Verdozzi Max Planck Institute for the Structure and Dynamics of Matter Luruper Chaussee 14922761HamburgGermany Center for Computational Quantum Physics(CCQ) The Flatiron Institute162 Fifth AvenueNew YorkNY10010USA Division of Mathematical Physics and ETSF Lund UniversityPO Box 11822100LundSweden

Magnetic skyrmions are topological excitations of great promise for compact and efficient memory ***,to interface skyrmionics with electronic devices requires efficient and reliable ways of creating and destroying such *** this work,we unravel the microscopic mechanism behind ultrafast skyrmion generation by femtosecond laser pulses in transition metal thin *** employ a theoretical approach based on a two-band electronic model,and show that by exciting the itinerant electronic subsystem with a femtosecond laser ultrafast skyrmion nucleation can occur on a 100 fs *** combining numerical simulations with an analytical treatment of the strong s–d exchange limit,we identify the coupling between electronic currents and the localized d-orbital spins,mediated via Rashba spin–orbit interactions among the itinerant electrons,as the microscopic and central mechanism leading to ultrafast skyrmion *** results show that an explicit treatment of itinerant electron dynamics is crucial to understand optical skyrmion generation.

关键词： excitation transition topological

Tuning MXenes Towards Their Use in Photocatalytic Water Splitting

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Energy & Environmental Materials 2024年第6期7卷 321-331页

作者： Diego Ontiveros Sergi Vela Francesc viñes Carmen Sousa Departament de Ciència de Materials i Química Física&Institut de Química Teòrica i Computacional(IQTCUB) Universitat de Barcelonac/Martíi Franquès 1-1108028 BarcelonaSpain

Finding appropriate photocatalysts for solar-driven water(h_(2)O)splitting to generate hydrogen(h_(2))fuel is a challenging task,particularly when guided by conventional trial-and-error experimental ***,density functional theory(DFT)is used to explore the MXenes photocatalytic properties,an emerging family of two-dimensional(2D)transition metal carbides and nitrides with chemical formula M_(n+1)X_(n)T_(x),known to be semiconductors when having T_(x)*** than 4,000 MXene structures have been screened,considering different compositional(M,X,T_(x),and n)and structural(stacking and termination position)factors,to find suitable MXenes with a bandgap in the visible region and band edges that align with the water-splitting half-reaction *** from bandgap analysis show how,in general,MXenes with n=1 and transition metals from group III present the most cases with bandgap and promising sizes,with C-MXenes being superior to *** band alignment calculations of candidate systems with a bandgap larger than 1.23 eV,the minimum required for a water-splitting process,Sc_(2)CT_(2),Y_(2)CT_(2)(T_(x)=Cl,Br,S,and Se)and Y_(2)CI_(2)are highlighted as adequate photocatalysts.

关键词： Density Functional Theory MXenes Photocatalysis Water Splitting

Comparative chemical sensor for detection of chromium(vi) in aqueous solution

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Optoelectronics Letters 2024年

作者： Sura h. al-Rekabi A.A.alwahib Electrical Technique Department， al Suwayrah Technical Institute， Middle Technical University Laser and Optoelectronics Department， University of Technology-Iraq

A process for purifying aqueous solutions containing heavy and toxic metals such as chromium has been investigated. One of the extremely harmful pollutants in rivers and seawater are the heavy metal ions due to their direct impact on human， animals and plants are hexavalent chromium Cr （vi）. Consequently， highly sensitive sensor to detect Chromium is essential. Surface Plasmon resonance （SPR） technique has attracted huge research interest in detecting heavy metals specifically. In this study， three types of prism-based SPR sensor; gold （Au）/silver （Ag）， Au/polyaniline （PANI） and Au/ titanium dioxide (TiO2) nanostructured films are investigated as potential sensing material to detect the presence of Cr （vi） ions in water. The base Au layer with thickness of 48.3 nm is deposited on a glass slide for all sensors. For Au/Ag， Au/PANI nanofibers and Au/ (TiO2) sensor films， the Cr （vi） concentration is varied from 1 to 15 ppm with sensitivity of 0.270 o ppm-1， 0.082o ppm-1and 0.039 o ppm-1 respectively. Based on these results， the Au/ PANI nanofibers are the most sensitive to chromium Cr （vi） among tested sensing materials.

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A comparative study between friction stir processing and friction stir vibration processing to develop magnesium surface nanocomposites

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International Journal of Minerals,Metallurgy and Materials 2020年第8期27卷 1133-1146页

作者： Behrouz Bagheri Mahmoud Abbasi Amin Abdollahzadeh amir hossein Kokabi Department of Mining and Metallurgy Amirkabir University of TechnologyTehranIran Faculty of Engineering University of KashanRavandi Blvd.KashanIran Department of Materials Science and Engineering Sharif University of TechnologyTehranIran Institute of Materials Engineering and Advanced Processes Department of Mining and MetallurgyAmirkabir University of TechnologyTehranIran

Friction stir processing(FSP)can be used to improve surface *** this study,a modified method of FSP called friction stir vibration processing(FSVP)was applied to develop a surface composite on AZ91 magnesium *** this technique,the workpiece is vibrated normal to the processing *** results illustrated that compared with the FSP method,the FSVP caused a better homogeneous distribution of SiC particles in the *** results also showed that matrix grains of friction stir vibration processed(FSV-processed)samples((26.43±2.00)μm)were finer than those of friction stir processed(FS-processed)specimens((39.43±2.00)μm).The results indicated that the ultimate tensile strength(UTS)of FSV-processed specimens(361.82 MPa)was higher than that of FS-processed specimens(324.97 MPa).The higher plastic strain in the material during FSVP,due to workpiece vibration,resulted in higher dynamic recrystallization,and consequently,finer grains were *** elongation and formability index of the FSV-processed specimen(16.88%and 6107.52 MPa·%,respectively)were higher than those of the FS-processed sample(15.24%and 4952.54 MPa·%,respectively).Moreover,the effects of FSVP were also found to intensify as the vibration frequency increased.

关键词： friction stir processing friction stir vibration processing surface composite mechanical properties microstructure

Controlling the magnetic state of the proximate quantum spin liquid α-RuCl_(3) with an optical cavity

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npj Computational Materials 2023年第1期9卷 265-274页

作者： Emil viñas Boström Adithya Sriram Martin Claassen Angel Rubio Max Planck Institute for the Structure and Dynamics of Matter Luruper Chaussee 14922761 HamburgGermany Department of Physics Stanford UniversityStanfordCA 94305USA Department of Physics and Astronomy University of PennsylvaniaPhiladelphiaPA 19104USA Center for Computational Quantum Physics Flatiron InstituteSimons FoundationNew York CityNY 10010USA

harnessing the enhanced light-matter coupling and quantum vacuum fluctuations resulting from mode volume compression in optical cavities is a promising route towards functionalizing quantum materials and realizing exotic states of ***,we extend cavity quantum electrodynamical materials engineering to correlated magnetic systems,by demonstrating that a Fabry-Pérot cavity can be used to control the magnetic state of the proximate quantum spin liquidα-RuCl_(3).Depending on specific cavity properties such as the mode frequency,photon occupation,and strength of the light-matter coupling,any of the magnetic phases supported by the extended Kitaev model can be *** particular,in the Thz regime,we show that the cavity vacuum fluctuations alone are sufficient to bringα-RuCl_(3) from a zigzag antiferromagnetic to a ferromagnetic *** external pumping of the cavity in the few photon limit,it is further possible to push the system into the antiferromagnetic Kitaev quantum spin liquid state.

关键词： state quantum magnetic

Microstructure, Mechanical Properties and Wear Behaviourof Deep-Cryogenic-Treated hSS

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材料热处理学报 2004年第5期25卷 540-545页

作者： V. Leskovek M. Kalin J. vi■intin Institute of Metals and Technology Ljubljana SloveniaUniversity of Ljubljana Center for Tribology and Technical Diagnostics Ljubljana SloveniaUniversity of Ljubljana Center for Tribology and Technical Diagnostics Ljubljana Slovenia

In this paper we compare the wear behaviour of a vacuum-heat-treated ESR AISI M2 high-speed steel and the same steel that was vacuum heat treated in conjunction with a deep-cryogenic treatment at -196 °C. Four different tempering temperatures for the specimens austenized at the same austenitizing temperature were carefully selected to obtain various in-advance-determined combinations of the microstructures, the fracture toughness, KIc and the Rockwell-C hardness. Each of the eight specimens was therefore characterised by these microstructures and resulting material properties. The wear study was performed using a reciprocating sliding device under well-controlled contact conditions. Relatively high loads were used to provide enough wear for a comparison of the selected samples. A much harder and dissimilar model counter-material, i.e. silicon nitride ceramic, was used in order to avoid excessive wear of the counter samples and adhesion, which could occur in contacts with similar materials (metals/steels) under such high loads and in non-lubricated conditions. The wear behaviours were then compared and discussed in terms of these microstructures and the related properties. The differences in the wear resistance obtained in our investigation were as high as an order of magnitude. however, the beneficial effects are not a direct result of the type of the treatment, but relate to a proper combination of the resulting fracture toughness and the hardness. The more uniform and moderate values, which, however, tend to be obtained with a deep-cryogenic treatment, are beneficial to the high wear resistance of the selected high-speed steel.

关键词：高速钢显微结构深低温处理机械性质磨损性能