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Experimental mass transfer coefficients in a pilot plant multistage column extractor

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Chinese Journal of Chemical engineering 2016年第8期24卷 989-999页

作者： Mehdi Asadollahzadeh Ahad Ghaemi Meisam Torab-Mostaedi Shahrokh Shahhosseini Department of Chemical engineering Iran University of Science and Technology (IUST) nuclear fuel cycle Research School Nuclear Science and Technology Research Institute

The volumetric overall mass transfer coefficients in a multistage column have been measured using axial dispersion model for toluene–acetone–water system. The effect of operating parameters on the volumetric overall mass transfer coefficients has been investigated for both mass transfer directions. The results show that the mass transfer performance is strongly dependent on rotor speed and mass transfer direction, although only slightly dependent on phase flow rates. In addition, empirical correlations to predict the overall mass transfer coefficients have been developed. The proposed correlations based on dimensionless numbers can be considered as a useful tool for the possible scale up of the multistage column extractor.

关键词： Multistage column Mass transfer coefficient Axial dispersion model Sherwood number

Conversion of CO into CO_(2) by high active and stable PdNi nanoparticles supported on a metal-organic framework

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Frontiers of Chemical Science and engineering 2022年第7期16卷 1139-1148页

作者： Fateme Abbasi Javad Karimi-Sabet Zeinab Abbasi Cyrus Ghotbi Department of Petroleum and Chemical engineering Sharif University of TechnologyTehranIran nuclear fuel cycle Research School Nuclear Science and Technology Research InstituteTehranIran

The solubility of Pd(NO_(3))_(2) in water is moderate whereas it is completely soluble in diluted HNO_(3) solution. Pd/MIL-101(Cr) and Pd/MIL-101-NH_(2)(Cr) were synthesized by aqueous solution of Pd(NO_(3))_(2) and Pd(NO_(3))_(2) solution in dilute HNO_(3) and used for CO oxidation reaction. The catalysts synthesized with Pd(NO_(3))_(2) solution in dilute HNO_(3) showed lower activity. The aqueous solution of Pd(NO_(3))_(2) was used for synthesis of mono-metal Ni, Pd and bimetallic PdNi nanoparticles with various molar ratios supported on MOF. Pd_(70)Ni_(30)/MIL-101(Cr) catalyst showed higher activity than monometallic counterparts and Pd+ Ni physical mixture due to the strong synergistic effect of PdNi nanoparticles, high distribution of PdNi nanoparticles, and lower dissociation and desorption barriers. Comparison of the catalysts synthesized by MIL-101(Cr) and MIL-101-NH_(2)(Cr) as the supports of metals showed that Pd/MIL-101-NH_(2)(Cr) outperforms Pd/MIL-101-(Cr) because of the higher electron density of Pd resulting from the electron donor ability of the NH_(2) functional group. However, the same activities were observed for Pd_(70)Ni_(30)/MIL-101(Cr) and Pd_(70)Ni_(30)/MIL-101-NH_(2)(Cr), which is due to a less uniform distribution of Pd nanoparticles in Pd_(70)Ni_(30)/MIL-101-NH_(2)(Cr) originated from amorphization of MIL-101-NH_(2)(Cr) structure during the reduction process. In contrast, Pd_(70)Ni_(30)/MIL-101(Cr) revealed the stable structure and activity during reduction and CO oxidation for a long time.

关键词： CO oxidation heterogeneous catalysis metal-organic framework NH_(2)functional group PdNi

Hydrothermal Formation of Lath-Shaped Trioctahedral Smectite with High Crystallinity

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Acta Geologica Sinica(English Edition) 2006年第2期80卷 290-295页

作者： Hirohisa YAMADA Kenji TAMURA Shingo YOKOYAMA Yujiro WATANABE Ecomaterials Center nuclear fuel cycle Back-end Research Center College of Environmental engineering and Architecture

Lath-shaped and highly crystalline trioctahedral smectites were synthesized under hydrothermal conditions. The quenched glasses with stoichiometrically dehydrated Na-smectite compositions were treated at （a） 500℃ and 100 MPa for 1 and 11 days; and （b） 300℃ and 100 MPa for 7 days. The crystallinity and particle size of products were dependent on the chemical composition of the starting glass, synthetic temperature and duration of hydrothermal treatment. The high structural ordering and large dimensions of the products were confirmed from the sharpness of XRD peaks; and hydration behavior under controlled relative humidity. Transmission electron microscopy was also performed for the characterization of the particle size of product. Particle sizes vary from ca. 10 nm to a few pm by changing the chemical compositions of the starting materials. The product with the highest structural ordering and largest dimension was obtained from Nao.33（Mg1.83Al0.67）Si4O11 glass treated at 500℃ and 100 MPa for 1 day. The obtained results also confirmed the metastability and compositional dependency in the formation of highly crystalline trioctahedral smectite at hydrothermal conditions.

关键词： high crystallinity hydration behavior hydrothermal formation lath-shaped trioctahedral smectite

Prediction of mass transfer coefficients in an asymmetric rotating disk contactor using effective diffusivity

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Chinese Journal of Chemical engineering 2017年第3期25卷 288-293页

作者： Meisam Torab-Mostaedi Mehdi Asadollahzadeh Jaber Safdari nuclear fuel cycle Research School Nuclear Science and Technology Research InstituteP.O.Box:11365-8486YehranIran

Mass transfer characteristics have been investigated in a 113 mm diameter asymmetric rotating disk contactor of the pilot plant scale for two different liquid–liquid systems. The effects of operating parameters including rotor speed and continuous and dispersed phase velocities on the volumetric overall mass transfer coefficients are investigated. The results show that the mass transfer performance is strongly dependent on agitation rate and interfacial tension, but only slightly dependent on phase flow rates. In this study, effective diffusivity is used instead of molecular diffusivity in the Grober equation for estimation of dispersed phase overall mass transfer *** enhancement factor is determined experimentally and there from an empirical expression is derived for prediction of the enhancement factor as a function of Reynolds number. The predicted results compared to the experimental data show that the proposed correlation can efficiently predict the overall mass transfer coefficients in asymmetric rotating disk contactors.

关键词： Asymmetric rotating disk contactor Mass transfer coefficient Enhancement factor Interfacial area Dispersed phase holdup

Radiation-Induced Luminescence for Applying to Retrospective Dosimetry

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Radiation-Induced Luminescence for Applying to Retrospective...

Life cycle assessment of oxygen-18 production using cryogenic oxygen distillation

作者： H.Fujita Y.Nakano T.Saito nuclear fuel cycle engineering laboratories JAEA

INTRODUCTION:It is well known that natural quartz exposed to prior ionizing radiation emits luminescence by subsequent exposure to heat or light,i.e.,thermoluminescence (TL) or optically stimulated luminescence (OSL),respectively(e.g.).These luminescence signals have been widely applied to dating and retrospective *** characteristics of natural quartz are dependent on their origins, thermal histories,impurity contents,***, emission mechanism of luminescence from Japanese quartz has not been explained,so far.

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来源： cnki会议评论

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Chinese Journal of Chemical engineering 2018年第9期26卷 1960-1966页

作者： Meysam Akbarian Shourkaei Abbas Rashidi Javad Karimi-Sabet Faculty of engineering University of Mazandaran Material and nuclear fuel Research School (MNFRS) Nuclear Science and Technology Research Institute

In this study, life cycle assessment of oxygen-18 by using cryogenic distillation of oxygen is performed using SimaPro 8.3 software. Life cycle assessment is performed to understand the environmental profile and hotspots of this process in order to be used in design and development. Simulation of oxygen-18 process is executed by Hysys software, and the required inputs and outputs for inventory of life cycle were acquired. By doing life cycle assessment and considering achieved results after characterization and normalization of inventory data it has been investigated that in the majority of environmental impacts electricity consumption has a huge contribution relative to other parts of the system like liquefied oxygen production from air separation unit,required facilities for air separation and oxygen-18 units, and needed transportation. Also, among 17 impact categories investigated in ReCiPe impact assessment method, fossil depletion, climate change(human health),particulate matter formation, climate change(ecosystem), human toxicity, and metal depletion have the most contribution in entire environmental loads respectively. Furthermore, sensitivity analysis showed that changing life cycle impact assessment method from ReCiPe to IMPACT 2002+ has no significant effect on acquired results and results are confident. In addition, assumption of market for depleted oxygen from heavy isotopes which is withdrawn from top of distillation columns showed some positive effects compared to first case and environmental impacts resulted from liquefied oxygen production(feed) reduced but because of huge contribution of electricity consumption compared to other sections, this positive effect has no remarkable influence on entire environmental loads of product system.

关键词： Life cycle assessment Oxygen- 18 production Cryogenic distillation Isotope separation

Probing the mass degeneracy of particles with different spins

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Chinese Physics C 2015年第5期39卷 1-3页

作者：张振华吕刚魏科伟 School of nuclear Science and Technology University of South China Cooperative Innovation Center for nuclear fuel cycle Technology & Equipment University of South China College of Science Henan University of Technology College of Physics and Electrical engineering Anyang Normal University

The spin is an important property of a particle. Although it is unlikely, there is still a possibility that two particles with different spins share similar masses. In this paper, we propose a method to probe this kind of mass degeneracy of particles with different spins. We use the cascade decay B^＋ →X（3872）K^＋, X（3872）→D^＋D^- to illustrate our method. It can be seen that the possible mass degeneracy of X（3872） can lead to interesting behavior in the corresponding cascade decay.

关键词： X(3872) mass degeneracy B meson

Use of axial dispersion model for determination of Sherwood number and mass transfer coefficients in a perforated rotating disc contactor

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Chinese Journal of Chemical engineering 2017年第1期25卷 53-61页

作者： Mehdi Asadollahzadeh Alireza Hemmati Meisam Torab-Mostaedi Mansour Shirvani Ahad Ghaemi Zahra Sadat Mohsenzadeh nuclear fuel cycle Research School Nuclear Science and Technology Research Institute P.O. Box： 11365-8486 Tehran Iran School of Chemical engineering Iron University of Science and Technology Tehran P.O. Box 16765-163 Iran Department of Chemical engineering Faculty of Engineering South Tehran Branch Islamic Azad University Iran

The mass transfer process in a perforated rotating disk contactor(PRDC) using a toluene-acetone-water system was *** volumetric overall mass transfer coefficients are calculated in a PRDC *** mass transfer directions are considered in *** influences of operating variables containing agitation rate,dispersed and continuous phase flow rates and mass transfer in the extraction column are *** to obtained results,mass transfer is significantly dependent on agitation rate,while the dispersed and continuous phase flow rates have a minor effect on mass transfer in the extraction ***,a novel empirical correlation is developed for prediction of overall continuous phase Sherwood number based on dispersed phase holdup,Reynolds number and mass transfer *** has been great agreement between experimental data and predicted values using a proposed correlation for all operating conditions.

关键词： Perforated rotating disk contactor Mass transfer coefficient dispersed phase holdup Interfacial area

Mechanical properties,thermal conductivity and defect formation energies of samarium immobilization in Gd_(2)Zr_(2)O_(7):First-principles study and irradiation experiment

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Journal of Rare Earths 2023年第3期41卷 422-433,I0004页

作者： Yuhao Wang Jiahu Ouyang Tao Wei Gui Cao Zhanguo Liu Zhaoying Ding Yujin Wang Yaming Wang Key Laboratory of Advanced Structural-Functional Integration Materials&Green Manufacturing Technology School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China nuclear fuel cycle Research Theme Australian Nuclear Science and Technology OrganisationLocked Bag 2001Kirrawee DCNSW2232Australia

A density functional theory(DFT)study was employed to investigate the mechanical property,thermal conductivity,Debye temperature,electronic structure and defect chemistry of(Gd_(1-x)Sm_(x))_(2)Zr_(2)O_(7).All the(Gd_(1-x)Sm_(x))_(2)Zr_(2)O_(7) compounds exhibit an excellent structural and mechanical stability(Gd_(0.25)Sm_(0.75))_(2)Zr_(2)O_(7) has the lowest Young’s modulus of 213.7 GPa,the largest Possion’s ratio of 0.292,the lowest Debye temperature of 491.8 K and the lowest thermal *** calculated thermal conductivities of(Gd_(1-x)Sm_(x))_(2)Zr_(2)O_(7) are 1.17-1.21 W/(m·K)by the Clark’s model and 1.32-1.36 W/(m·K)by the Cahall’s model,*** formation energies of O vacancies at 48f site are negative,which increase with the Sm content,however,the formation energies of O vacancies at 8b site are almost *** addition,Sm partly occupying the Gd-site reduces distinctly the formation energies of defects such as A-site vacancies,cation antisite defects,anion Frenkel pairs of oxygen at 8b site and cation interstitials,which suggests that Sm-doped Gd_(2)Zr_(2)O_(7),especially equimolar GdSmZr_(2)O_(7),has a better irradiation *** the 16 MeVTa-ion irradiation at a fluence of 1×10^(14) or 2×10^(14) ions/cm^(2),the crystal structure of GdSmZr_(2)O_(7) transforms from pyrochlore to a defect fluorite without obvious amorphous phase.

关键词： Pyrochlores First-principles calculations Mechanical properties Defect formation energies Ion irradiation Rare earths