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Removal of organic pollutants by lanthanide-doped mIL-53(Fe) metal-organic frameworks:Effect of dopant type in magnetite precursor

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Journal of Rare Earths 2023年第1期41卷 140-148页

作者： Shim.a.m.a.i Khadija m.emran Fedaa m.m.a.rashedee Department of Chemistry Faculty of ScienceCairo University.Giza12613Egypt Department of Chemistry Faculty of ScienceTaibah UniversityMadinah30002Saudi Arabia

A series of undoped and lanthanide doped mIL-53(Fe)/Ln-Fe_(3)O_(4)(Ln=La,Nd,or Gd) metal-organic frameworks(mOFs) were prepared by the solvothermal *** prepared samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Brunauer-Emmett-Teller(BET) m.a.urements,scanning electron microscopy(SEm),and thermal *** and FT-IR results ascertain the successful mOF formation for all prepared ***-53(Fe)/La-Fe_(3)O_(4) has the smallest particle size of 8.6 nm,the largest BET surface area of 54.2 m^(2)/g,and the highest *** and different lanthanide doped mIL-53(Fe) we re employed as sorbents for the removal of methylene blue(mB)dye from.a.ueous solutions to examine the doping benefit and the effect of the dopant size on the sorption *** causes mOFs to act as pH-independent sorbents,which make it applicable at any *** follows pseudo-second-order kinetic model,and doped sorbents attain equilibrium *** isotherms are followed,except for mIL-53(Fe)/La-Fe_(3)O_(4).The adsorption capacity increases with increasing the dopant ion size,100.5 mg/g for La-doped mOF,which is about four times higher than that of undoped *** adsorption mechanism involves chemical interactions between Lewis acid in magnetite mIL-53(Fe) series and Lewis base in mB.

关键词： Lanthanide metal organic framework Adsorption Doping Organic dyes Rare earths

Fabrication of Bi_2O_3/TiO_2nanocomposites and their applications to the degradation of pollutants in air and water under visible-light

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Journal of Environmental Sciences 2014年第2期26卷 458-465页

作者： Ashok Kumar Chakraborty md emran Hossain md masudur Rhaman K m.a.Sobahan Department of Applied Chemistry and Chemical Technology Islamic University Department of Applied Physics Electronics and Communication Engineering Islamic University

A nanoheterojunction composite photocatalyst Bi2O3/TiO2 working under visible-light （λ≥ 420 nm） was prepared by combining two semiconductors Bi2O3 and TiO2 varying the Bi2O3/TiO2 molar ratio. maleic acid was employed as an organic binder to unite Bi2O3 and TiO2 nanoparticles. The SEm, TEm, XRD and diffuse reflectance spectra were utilized to characterize the prepared Bi2O3/TiO2 nanoheterojunction. The nanocomposite exhibited unusual high photocatalytic activity in decomposing 2-propanol in gas phase and phenol in aqueous phase and, evolution of CO2 under visible light irradiation while the end members exhibited low photocatalytic activity. The composite was optimized to 5 mol% Bi2O3/TiO2. The remarkable high photocatalytic efficiency originates from the unique relative energy band position of Bi2O3 and TiO2 as well as the absorption of visible light by Bi2O3.

关键词： nanoheterojunction Bi2O3/TiO2 composite photocatalyst pollutants visible-light

Insights into the physical properties and anisotropic nature of ErPdBi with an appearance of low minimum thermal conductivity

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Chinese Physics B 2021年第1期30卷 398-406页

作者： S K mitro R majumder K m Hossain md Zahid Hasan md emran Hossain m.a.Hadi Bangamata Sheikh Fojilatunnesa mujib Science and Technology University Jamalpur-2012Bangladesh Physics Discipline Khulna UniversityKhulna-9208Bangladesh Department of materials Science and Engineering University of RajshahiRajshahi-6205Bangladesh Department of Electrical and Electronic Engineering International Islamic University ChittagongKumiraChittagong-4318Bangladesh Department of Physics University of RajshahiRajshahi6205Bangladesh

We theoretically study the structural, elastic and optical properties of Er Pd Bi together with its anisotropic behaviors using density functional theory. It is observed that Er Pd Bi satisfies the Born stability criteria nicely and possesses high quality of machinability. The anisotropic behavior of Er Pd Bi is reported with the help of theoretical anisotropy indices incorporating 3 D graphical presentation, which suggests that Er Pd Bi is highly anisotropic in nature. It is noticed that the minimum thermal conductivity is very low for Er Pd Bi com.a.ed to the several species. This low value of minimum thermal conductivity introduces the potentiality of Er Pd Bi in high-temperature applications such as thermal barrier *** addition, deep optical insights of Er Pd Bi reveal that our material can be used in different optoelectronic and electronic device applications ranging from organic light-emitting diodes, solar panel efficiency, waveguides etc. to integration of integrated circuits. Therefore, we believe that our results will provide a new insight into high-temperature applications and will benefit for the development of promising optoelectric devices as well.

关键词： Er Pd Bi minimum thermal conductivity anisotropy density functional theory(DFT)

Temperature effect on the corrosion and passivation characterization of Ni_(82.3)Cr_7Fe_3Si_(4.5)B_(3.2) alloy in acidic media

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International Journal of minerals,metallurgy and materials 2016年第2期23卷 205-214页

作者： Khadijah m.emran Sanaa T.Arab Aisha m.a.-Turkustani Hamad A.Al-Turaif Chemistry Department Faculty of Science Taibah University Department of Chemistry Faculty of Sciences Al-Faisaliah King Abdulaziz University Department of Chemical and materials Engineering King Abdulaziz University

The effects of temperature on corrosion and the electrochemical behavior of Ni82.3Cr7Fe3Si4.5B3.2 glassy alloy in HC1,H2SO4,and H3PO4 acids were studied using AC and DC *** data reveal that the susceptibility to localized corrosion increases with increasing *** polarization curves reveal that the bulk glassy alloy is spontaneously passivated at all the investigated temperature in H2SO4 and H3PO4 solutions.A localized corrosion effect in HCl solution is clearly *** apparent activation energies in the regions of Tafel,active,and passive,as well as the enthalpies and entropies of the dissolution process were determined and *** high apparent activation energy（Ea） value for H3PO4 solution in Tafel region is explained by the low aggressivity of PO4^3- ions.

关键词： nickel alloys corrosion temperature effect acidic environment passivation polarization

Numerical storm surge model with higher order finite difference method of lines for the coast of Bangladesh

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Acta Oceanologica Sinica 2019年第6期38卷 100-116页

作者： Gour Chandra Paul md. emran Ali Department of mathematics University of RajshahiRajshahi 6205Bangladesh Department of Textile Engineering Northern University BangladeshDhaka 1230Bangladesh

In this study, the method of lines (mOLs) with higher order central difference approximation method coupled with the classical fourth order Runge-Kutta (RK(4,4)) method is used in solving shallow water equations (SWEs) in Cartesian coordinates to foresee water levels associated with a storm.a.curately along the coast of Bangladesh. In doing so, the partial derivatives of the SWEs with respect to the space variables were discretized with 5-point central difference, as a test case, to obtain a system of ordinary differential equations with time as an independent variable for every spatial grid point, which with initial conditions were solved by the RK(4,4) method. The complex land-sea interface and bottom topographic details were incorporated closely using nested schemes. The coastal and island boundaries were rectangularized through proper stair step representation, and the storing positions of the scalar and momentum variables were specified according to the rules of structured C-grid. A stable tidal regime was made over the model domain considering the effect of the major tidal constituent, m2 along the southern open boundary of the outermost parent scheme. The meghna River fresh water discharge was taken into account for the inner most child scheme. To take into account the dynamic interaction of tide and surge, the generated tidal regime was introduced as the initial state of the sea, and the surge was then made to come over it through computer simulation. Numerical experiments were performed with the cyclone April 1991 to simulate water levels due to tide, surge, and their interaction at different stations along the coast of Bangladesh. Our computed results were found to com.a.e reasonable well with the limited observed data obtained from Bangladesh Inland Water Transport Authority (BIWTA) and were found to be better in com.a.ison with the results obtained through the regular finite difference method and the 3-point central difference mOLs coupled with the RK(4,

关键词： shallow water equations method of lines higher order finite difference approximation method surge nested scheme

modeling and Analysis of Electrostatically Actuated mEmS under Combined Nonlinearities, Lorentz Force, and mechanical Shock

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Journal of Control Science and Engineering 2016年第2期4卷 82-89页

作者： emran Khoshrouye Ghiasi Department of mechanical Engineering Ferdowsi University of Mashhad Mashhad 96911 Iran

This paper shows an analysis ofmEm S （micro electro mechanical systems） due to Lorentz force and mechanical shock. The formulation is based on a modified couple stress theory, the von Karman geometric nonlinearity and Reynolds equation as well. The model contains a silicon microbeam, which is encircled by a stationary plate. The non-dimensional governing equations and associated boundary conditions are then solved iteratively through the Galerkin weighted method. The results show that pull-in voltage is dependent on the geometry nonlinearity. It is also demonstrated that by increasing voltage between the silicon microbeam.a.d stationary plate, the pull-in instability happens.

关键词： m Em S mechanical shock nonlinearity pull-in Galerkin weighted method dimensionless parameters.

Fabrication and Characterization of Lanthanide-TiO₂ Nanotube Composites

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Open Journal of Physical Chemistry 2023年第2期13卷 13-28页

作者： Khadijah m. emran Hessah E. Alanazi Department of Chemistry College of Science Taibah University Madinah KSA Department of Chemistry College of Science and Art Al Jouf University Qurayyat KSA

Titanium dioxide (TiO2) doped with neodymium (Nd) and/or Gadolinium (Gd) rare-earth elements were fabricated into nanotubes via the hydrothermal method in a KOH solution and in-situ doping. Titanium dioxide nanotubes (TNTs) and in-situ Nd-doped and/or Gd-doped TNTs were characterized with transmission and scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, Raman spectroscopy, and Fourier-transform infrared spectroscopy. morphologies indicated a network of aggregated nanotubes. The phase and composition analyses revealed that the lanthanide TNTs had anatase phases with Nd and/or Gd nanoparticles in the TNT lattice. The nanoparticles were uniformly deposited on the surface because of hydroxyl groups on the TNT surfaces, resulting in a very high loading density. The outer diameter and the length of the TNTs increased with doping. The mechanisms for the formation of multiwall TNTs are discussed.

关键词： TiO2 Nanotube Lanthanide Doped Hydrothermal XRD TEm Raman Spectroscopy

Discrepancy in Grain Size Estimation of H_(2)O Ice in the Outer Solar System

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Research in Astronomy and Astrophysics 2023年第3期23卷 128-142页

作者： A.emran V.F.Chevrier Space and Planetary Sciences University of ArkansasFayettevilleAR 72701USA

Radiative transfer models(RTms) have been used to estimate grain size of amorphous and crystalline water(H_(2)O)ice in the outer solar system from near-infrared(NIR) wavelengths. We use radiative scattering models to assess the discrepancy in grain size estimation of H_(2)O ice at a temperature of 15, 40, 60, and 80 K(amorphous) and 20,40, 60, and 80 K(crystalline)—relevant to the outer solar system. We com.a.e the single scattering albedos of H_(2)O ice phases using the mie theory and Hapke approximation models from the optical constant at NIR wavelengths(1–5 μm). This study reveals that Hapke approximation models—Hapke slab and internal scattering model(ISm)—predict grain size of crystalline phase slightly closer to mie model than amorphous phase at temperatures of 15–80 K. However, the Hapke slab model predicts, in general, grain sizes much closer to those of the mie model’s estimations while ISm predicted grain sizes exhibit a higher uncertainty. We recommend using the mie model for unknown spectra of outer solar system bodies to estimate H_(2)O ice grain sizes. While choosing the approximation model for employing RTms, we recommend using a Hapke slab approximation model over the ISm.

关键词： sizes crystalline closer

Solution of a One-Dimension Heat Equation Using Higher-Order Finite Difference methods and Their Stability

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Journal of Applied mathematics and Physics 2022年第3期10卷 877-886页

作者： m. emran Ali Wahida Zaman Loskor Sam.a.Taher Farjana Bilkis Department of Textile Engineering Northern University Bangladesh Dhaka Bangladesh Department of Science and Humanities Bangladesh Army International University of Science & Technology Cumilla Bangladesh

One-dimensional heat equation was solved for different higher-order finite difference schemes, namely, forward time and fourth-order centered space explicit method, backward time and fourth-order centered space implicit method, and fourth-order implicit Crank-Nicolson finite difference method. Higher-order schemes have complexity in computing values at the neighboring points to the boundaries. It is required there a specification of the values of field variables at some points exterior to the domain. The complexity was incorporated using Hicks approximation. The convergence and stability analysis was also computed for those higher-order finite difference explicit and implicit methods in case of solving a one dimensional heat equation. The obtained numerical results were com.a.ed with exact solutions. It is found that backward time and fourth-order centered space implicit scheme along with Hicks approximation performed well over the other mentioned higher-order approaches.

关键词： Heat Equation Boundary Condition Higher-Order Finite Difference methods Hicks Approximation