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Ru/NimnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

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Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： md Ahasan Habib Shusen Lin mehedi Hasan joni Sumiya Akter Dristy Rutuja mandavkar Jae-Hun Jeong Jihoon Lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NimnB spherical cluster pillar （SCP）,denoted as Ru/NimnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NimnB matrix revealed significant improvements in electrocatalytic *** Ru/NimnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 m KOH,making them highly competitive with state-of-the-art ***,the Ru/NimnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 m KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NimnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 m KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NimnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NimnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Advanced electrocatalyst High current Corrosion resistance Industrial requirement

Seasonal comparison of moss bag technique against vertical snow samples for monitoring atmospheric pollution

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Journal of Environmental Sciences 2016年第3期28卷 128-137页

作者： Hanna Salo Anna-Kaisa Berisha joni m?kinen Department of Geography and Geology University of Turku Centre for Research of Lifelong Learning and Education(CELE) University of Turku

This is the first study seasonally applying Sphagnum papillosum moss bags and vertical snow samples for monitoring atmospheric *** bags,exposed in January,were collected together with snow samples by early march 2012 near the Harjavalta Industrial Park in southwest ***,chemical,scanning electron microscopy-energy dispersive X-ray spectroscopy（SEm-EDX）,K-means clustering,and Tomlinson pollution load index（PLI）data showed parallel spatial trends of pollution dispersal for both *** strengthen previous findings that concentrate and slag handling activities were important（dust）emission sources while the impact from Cu–Ni smelter＇s pipe remained secondary at closer *** significant correlations existed between the variables of snow and moss *** a summary,both methods work well for sampling and are efficient pollutant *** bags can be used also in winter conditions and they provide more homogeneous and better controlled sampling method than snow samples.

关键词： Biomonitoring Industrial pollution Heavy metal magnetic susceptibility Scanning electron microscopy-energy dispersive X-ray spectroscopy

Global optimum of microstructure parameters in the CmWP line-profile-analysis method by combining marquardt-Levenberg and monte-Carlo procedures

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Journal of materials Science & Technology 2019年第7期35卷 1508-1514页

作者： Gabor Ribarik Bertalan joni Tamas Ungar Department of materials Physics Edtvos University BudapestPO Box 32H-15J8Hungary School of materials The University of ManchesterM139PLUK

Line profile analysis of X-ray and neutron diffraction patterns is a powerful tool for determining the microstructure of crystalline materials. The Convolutional-multiple-Whole-Profile (CmWP) procedure is based on physical profile functions for dislocations, domain size, stacking faults and twin boundaries. Order dependence, strain anisotropy, hkl dependent broadening of planar defects and peak shape are used to separate the effect of different lattice defect types. The marquardt-Levenberg (mL) numerical optimiza-tion procedure has been used successfully to determine crystal defect types and densities. However, in more complex cases like hexagonal materials or multiple phases the mL procedure alone reveals uncer-tainties. In a new approach the mL and a monte-Carlo statistical method are combined in an alternative manner. The new CmWP procedure eliminates uncertainties and provides globally optimized parameters.

关键词： X-ray line profile analysis Neutron line profile analysis CmWP Global optimum Dislocation densities Grain size Planar defects monte-Carlo method

Influence of emergent macrophyte (Phragmites australis) density on water turbulence and erosion of organic-rich sediment

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Journal of Hydrodynamics 2013年第2期25卷 288-293页

作者： HORPPILA Jukka KAITARANTA joni JOENSUU Laura NURmINEN Leena Department of Environmental Sciences University of Helsinki

The effects of the emergent macrophyte Phragmites australis on water turbulence, bottom shear velocity and water turbidity were experimentally studied with the stem densities 0 stems/m2-100 stems/m2 and using organic-rich sediment. It is found that the maximum root-mean-square （rms） velocity and shear velocity decrease linearly with increasing stem density. By affecting the height of peak turbulence values, emergent plants can thus lower the frequency of sediment erosion events. Additionally, the slope of the rms turbulence increment decreases with increasing stem density. Thus, also the duration of strong turbulence is affected by the density of emergent macrophytes. The critical shear velocity for sediment resuspension is 0.0035 m/s-0.0055 rn/s and not affected by the stem density. In the absence of macrophytes, water flow causes a 6.3-fold increment in turbidity, but with macrophytes turbidity values remain lower. The experiments suggest that even relatively low densities of Phragmites can have substantial effects on water turbulence and consequently on water quality.

关键词： emergent macrophytes turbulence shear velocity resuspension turbidity

Investigation of the passive behaviour of AZ31B alloy in alkaline solutions

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Journal of magnesium and Alloys 2014年第2期2卷 175-180页

作者： A.Fattah-alhosseini m.Sabaghi joni Faculty of Engineering Bu-Ali Sina UniversityHamedan 65178-38695Iran

In this work,the passivity of AZ31B alloy in NaOH solutions was studied by potentiodynamic polarization,electrochemical impedance spectroscopy(EIS)and mott-Schottky *** polarization results indicated that decreasing NaOH concentration leads to decrease the corrosion rate of this *** results showed that the reciprocal capacitance(1/C)of the passive film is directly proportional to its thickness which increases with decreasing NaOH ***,it is clear that dilute NaOH solutions offer better conditions for forming the passive films with higher protection behaviour,due to the growth of a much thicker and less defective *** mott-Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics,where the oxygen vacancies and interstitials(over the cation vacancies)***,mott-Schottky results showed that the donor densities evaluated from mott-Schottky plots are in the range of 10^(20) cm^(−3) and decreased with decreasing NaOH concentration.

关键词： AZ31B alloy EIS mott-Schottky NaOH Passive film

Semiconducting behavior of the anodically passive films formed on AZ31B alloy

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Journal of magnesium and Alloys 2014年第4期2卷 305-308页

作者： A.Fattah-alhosseini m.Sabaghi joni Faculty of Engineering Bu-Ali Sina UniversityHamedan 65178-38695Iran

This work includes determination of the semiconductor character and estimation of the dopant levels in the passive film formed on AZ31B alloy in 0.01 m NaOH,as well as the estimation of the passive film thickness as a function of the film formation ***-Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics,where the oxygen vacancies and interstitials *** on the mott-Schottky analysis,it was shown that the calculated donor density increases linearly with increasing the formation ***,the electrochemical impedance spectroscopy(EIS)results indicated that the thickness of the passive film was decreased linearly with increasing the formation *** results showed that decreasing the formation potential offer better conditions for forming the passive films with higher protection behavior,due to the growth of a much thicker and less defective films.

关键词： AZ31B alloy mott-Schottky Formation potential Donor density

Estimation of postseismic deformation parameters from continuous GPS data in northern Sumatra after the 2004 Sumatra-Andaman earthquake

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Earthquake Science 2015年第5期28卷 347-352页

作者： Bimar Anugrah Irwan meilano Endra Gunawan joni Efendi Geodesy and Geomatics Engineering Faculty of Earth Science and TechnologyBandung Institute of Technology Graduate Research on Earthquake and Active Tectonics Faculty of Earth Science and TechnologyBandung Institute of Technology Geospatial Information Agency

Continuous global positioning system （GPS） in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the m9.2 2004 Sumatra-Andaman earthquake. We analyze the character- istics of postseismic deformation of the 2004 earthquake based on GPS networks operated by BIG, and the others named AGNeSS, and SuGAr networks located in northern Sumatra. We use a simple analytical logarithmic and exponential function to evaluate the postseismic deforma- tion parameters of the 2004 earthquake. We find that GPS data in northern Sumatra during time periods of 2005-2012 are fit better using the logarithmic function with dog of 104.2 ± 0.1 than using the exponential function. Our result clearly indicates that other physical mechanisms of post- seismic deformation should be taken into account rather than a single physical mechanism of afterslip only.

关键词： The 2004 Sumatra-Andaman earthquakeContinuous GPS data Logarithmic and exponential functions

Time Dependent Wave Propagation modeling Using Finite Difference Scheme of 2D Wave Equation Based on Absorbing and Reflecting Boundaries

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Journal of Applied mathematics and Physics 2021年第9期9卷 2334-2344页

作者： m. joni Alam W. Z. Loskor m. mohiuddin Department of mathematics Comilla University Cumilla Bangladesh Department of Science and Humanities Bangladesh Army International University of Science and Technology Cumilla Bangladesh

Boundary procedure is an important phenomenon in numerical simulation. To reduce or eliminate the spurious reflections significantly which is occurred in boundary is a challenging and vital approach. The appropriate artificial numerical boundaries can be applied to eliminate the effect of unnecessary spurious reflections in case of the numerical simulations of wave propagation phenomena problems. Typically, to reduce the artificial reflections, the absorbing boundary conditions are necessary. In this paper, we overview and investigate the appropriate typical absorbing boundary conditions and analyzed the boundary effect of two dimensional wave equation numerically. Reflections over the wide-ranging incident angles are complicated to eliminate, but the absorbing boundary conditions that we have applied are computationally cost efficient, easy to apply and able to reduce reflections significantly. For numerical solution, finite difference method is applied to develop numerical scheme using 2D wave equation. Using the developed numerical scheme, we obtain the numerical solution of the governing equation as an initial boundary value problem and realize the qualitative behavior of the solution in infinite space. The finite difference numerical scheme has been investigated by developing mATLAB programming language code. Numerical results have been discussed and analyzed with presenting different qualitative behavior of the numerical scheme. The accuracy and efficiency of the numerical scheme has been illustrated. The stability analysis was discussed and verified stability condition. Using the numerical scheme and absorbing boundary conditions, the boundary effects and absorption of spurious reflection of boundary have been demonstrated.

关键词： Absorbing Boundary Conditions 2D Wave Equation Finite Difference method Numerical Solution

On secondary new particle formation in China

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Frontiers of Environmental Science & Engineering 2016年第5期10卷 191-200页

作者： markku Kulmala Tuukka Petaja Veli-matti Kerminen joni Kujansuu Taina Ruuskanen Aijun Ding Wei Nie min HU Zhibin Wang Zhijun Wu Lin Wang Douglas R. Worsnop University of Helsinki P.O. Box 64 Helsinki 00014 Finland Joint Intemational Research Laboratory of Atmospheric and Earth System Sciences (JirLATEST) Nanjing University and University of Helsinki Nanjing 210093 China Institute for Climate and Global Change Research Nanjing University Nanjing 210000 China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing 100871 China max Planck Institute for Chemistry Hahn-Meimer-Weg 1 Mainz DE 55128 Germany Department of Environmental Science & Engineering Fudan University Shanghai 200433 China Aerodyne Research Inc. Billerica MA 01821 USA

Formation of new atmospheric aerosol particles is a global phenomenon that has been observed to take place in even heavily-polluted environments. However, in all environments there appears to be a threshold value of the condensation sink （due to pre-existing aerosol particles） after which the formation rate of 3 nm particles is no longer detected. In China new particle production has been observed at very high pollution levels （condensation sink about 0.1 s-1 ） m several megaclt es, including Beijing, Shanghai and Nanjing as well as in Pearl River Delta （PRD）. Here we summarize the recent findings obtained from these studies and discuss the various implications these findings will have on future research and policy.

关键词： Aerosol particles Heavily-polluted environments Condensation sink New particle production megacities