Unusual behavior of MgFe2O4 during regeneration: desorption versus specific adsorption

2019 ◽  
Vol 80 (4) ◽  
pp. 654-658 ◽  
Author(s):  
A. I. Ivanets ◽  
V. G. Prozorovich ◽  
M. Yu. Roshchina ◽  
V. Srivastava ◽  
M. Sillanpää
Keyword(s):  
High Efficiency ◽  
Theory And Practice ◽  
Specific Adsorption ◽  
Main Process ◽  
Adsorption Efficiency ◽  
Practical Application ◽  
Unusual Behavior ◽  
Adsorption Sites ◽  
Regeneration Efficiency ◽  
Mb Adsorption

Abstract The reusability of spent adsorbents is the most important characteristic for their practical application. The process of MgFe2O4 regeneration after methylene blue (MB) adsorption was studied. The effect of the nature (HCl, HNO3, and MgCl2) and the concentration (10−3–10−1 M) of regeneration agents was established. All the regeneration agents at 10−3 and 10−2 M had high efficiency and adsorption capacity recovery reached 80–90%, whereas for 10−1 M concentration the adsorption efficiency was in the range of 4.5–36.2%. It was shown that the concentration of desorbed MB was much less than what had been previously adsorbed and did not correlate with regeneration efficiency. The unusual behavior of MgFe2O4 during regeneration could be due to different mechanisms of regeneration by OH3+ and Mg2+ ions: (i) for acidic regeneration the main process was the non-specific adsorption of OH3+ ions in a diffusion layer and the substitution of adsorbed MB due to electrostatic forces; (ii) in the case of Mg2+ as a regeneration agent, there was specific adsorption due to the completion of a crystal lattice of MgFe2O4 nanoparticles by Mg2+ ions (according to the rules of Fayans-Pannet) with the formation of new Mg-OH adsorption sites and the super-equivalent adsorption of Mg2+ ions (according to DLVO (Derjaguin, Landau, Verwey, and Overbeek) theory) accompanied by a recharge of the MgFe2O4 surface. These phenomena of MgFe2O4 regeneration using Mg2+ ions must be taken into account in the theory and practice of adsorption.

scholarly journals The Main Progress of Perovskite Solar Cells in 2020–2021

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Tianhao Wu ◽  
Zhenzhen Qin ◽  
Yanbo Wang ◽  
Yongzhen Wu ◽  
Wei Chen ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Perovskite Solar Cells ◽  
Lead Free ◽  
Manufacturing Cost ◽  
Practical Application ◽  
The World ◽  
Photovoltaic Technology

AbstractPerovskite solar cells (PSCs) emerging as a promising photovoltaic technology with high efficiency and low manufacturing cost have attracted the attention from all over the world. Both the efficiency and stability of PSCs have increased steadily in recent years, and the research on reducing lead leakage and developing eco-friendly lead-free perovskites pushes forward the commercialization of PSCs step by step. This review summarizes the main progress of PSCs in 2020 and 2021 from the aspects of efficiency, stability, perovskite-based tandem devices, and lead-free PSCs. Moreover, a brief discussion on the development of PSC modules and its challenges toward practical application is provided.

A membrane biofilm reactor achieves aerobic methane oxidation coupled to denitrification (AME-D) with high efficiency

2008 ◽  
Vol 58 (1) ◽  
pp. 83-87 ◽  
Author(s):  
O. Modin ◽  
K. Fukushi ◽  
F. Nakajima ◽  
K. Yamamoto
Keyword(s):  
Methane Oxidation ◽  
High Efficiency ◽  
Biofilm Reactor ◽  
Practical Application ◽  
Suspended Culture ◽  
Consumption Ratio ◽  
Membrane Biofilm Reactor ◽  
Nitrate Consumption ◽  
Attached Culture ◽  
Aerobic Methanotrophs

Methane would potentially be an inexpensive, widely available electron donor for denitrification of wastewaters poor in organics. Currently, no methanotrophic microbe is known to denitrify. However, aerobic methane oxidation coupled to denitrification (AME-D) has been observed in several laboratory studies. In the AME-D process, aerobic methanotrophs oxidise methane and release organic metabolites and lysis products, which are used by coexisting denitrifiers as electron donors for denitrification. Due to the presence of oxygen, the denitrification efficiency in terms of methane-to-nitrate consumption is usually low. To improve this efficiency the use of a membrane biofilm reactor was investigated. The denitrification efficiency of an AME-D culture in (1) a suspended growth reactor, and (2) a membrane biofilm reactor was studied. The methane-to-nitrate consumption ratio for the suspended culture was 8.7. For the membrane-attached culture the ratio was 2.2. The results clearly indicated that the membrane-attached biofilm was superior to the suspended culture in terms of denitrification efficiency. This study showed that for practical application of the AME-D process, focus should be placed on development of a biofilm reactor.

scholarly journals On Performance of Sparse Fast Fourier Transform Algorithms Using the Aliasing Filter

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1117
Author(s):  
Bin Li ◽  
Zhikang Jiang ◽  
Jie Chen
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
High Efficiency ◽  
Theory And Practice ◽  
Long Time ◽  
And Performance ◽  
Binary Tree Search ◽  
The One ◽  
Sparse Fast Fourier Transform ◽  
L1 And L2

Computing the sparse fast Fourier transform (sFFT) has emerged as a critical topic for a long time because of its high efficiency and wide practicability. More than twenty different sFFT algorithms compute discrete Fourier transform (DFT) by their unique methods so far. In order to use them properly, the urgent topic of great concern is how to analyze and evaluate the performance of these algorithms in theory and practice. This paper mainly discusses the technology and performance of sFFT algorithms using the aliasing filter. In the first part, the paper introduces the three frameworks: the one-shot framework based on the compressed sensing (CS) solver, the peeling framework based on the bipartite graph and the iterative framework based on the binary tree search. Then, we obtain the conclusion of the performance of six corresponding algorithms: the sFFT-DT1.0, sFFT-DT2.0, sFFT-DT3.0, FFAST, R-FFAST, and DSFFT algorithms in theory. In the second part, we make two categories of experiments for computing the signals of different SNRs, different lengths, and different sparsities by a standard testing platform and record the run time, the percentage of the signal sampled, and the L0, L1, and L2 errors both in the exactly sparse case and the general sparse case. The results of these performance analyses are our guide to optimize these algorithms and use them selectively.

scholarly journals The fundamental concepts of cultural anthropology applied in the theory and practice of the anthropological theater

2021 ◽  
pp. 1-10
Author(s):  
Polina Mikhailovna Stepanova
Keyword(s):  
Cultural Anthropology ◽  
Modern Art ◽  
Theory And Practice ◽  
Practical Application ◽  
Social Anthropology ◽  
The Past ◽  
Practical Tool ◽  
Key Terms ◽  
Jerzy Grotowski ◽  
Experimental Stage

This article explores the classical terms and concepts of cultural anthropology, which have found practical application in the performances, paratheatrical experiments and actions of the Polish experimental stage director Jerzy Grotowski (1933–1999) and collectives of the modern anthropological theater that continue the pursuits of Grotowski of the late XX century. The methods and terms of cultural (social) anthropology by A. van Gennep, V. Turner, M. Eliade, B. Malinowski and structural anthropology by C. Levi-Strauss give a better perspective on the specific terminological apparatus of Grotowski, unique practical discoveries of his works, and conceptual basis of theatrical anthropology as one of the paramount phenomena in the development of modern art. This article is first to discuss the problems of the emergence and formation of anthropological methodology as the framework for creating a scientific apparatus for understanding ritual-theatrical forms, as well as practical tool for artistic expression in the theatrical and paratheatrical experiments. Based on the fundamental works of the school of cultural anthropology, the author reveals the key terms of modern anthropological theater. As a result of studying the methods and approaches of cultural anthropology, the author determines the new unique technique of the modern Polish theater ensembles based not on the reconstruction of theatrical forms of the past, but rather reactualization of the mythological structures in the process of creating ritual-theatrical action.

Of rhizomes and pointillism: David john farmerʼs influence, method and art in the field

2016 ◽  
Vol 19 (1) ◽  
pp. 30-44
Author(s):  
Richard Huff ◽  
Cynthia Cors ◽  
Jinzhou Song ◽  
Yali Pang
Keyword(s):  
Public Policy ◽  
Public Administration ◽  
Theory And Practice ◽  
Research Approach ◽  
Practical Application ◽  
Vast Array ◽  
The Public

The work of David John Farmer has been recognized as critical to the Public Policy and Administration canon. Its impact has been far-reaching both geographically because of its international application and theoretically because of the vast array of public administration challenges it can help resolve. This paper uses the concepts of rhizomatic thinking and reflexive interpretation to describe Farmerʼs work. And because a critical piece of Farmerʼs work is a bridging of the gap between theory and practice, it formally introduces Farmerʼs research approach as Farmerʼs Method. This article is intended to serve as a useful tool for students, practitioners, and theorists in understanding the vast contributions of David John Farmer and the practical application of his work.

Searching for a high efficiency and environmental benign reagent to leach ion-adsorption rare earths based on the zeta potential of clay particles

2018 ◽  
Vol 20 (19) ◽  
pp. 4528-4536 ◽  
Author(s):  
Lifen Yang ◽  
Dashan Wang ◽  
Cuicui Li ◽  
Yuanyuan Sun ◽  
Xuezhen Zhou ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Rare Earths ◽  
Aluminum Sulfate ◽  
High Efficiency ◽  
Specific Adsorption ◽  
Environmentally Benign ◽  
Ion Adsorption ◽  
Clay Particles ◽  
Highly Efficient

Aluminum sulfate is the best reagent for highly efficient and environmentally benign leaching of IAREs because of its specific adsorption towards CPs.

Moving between theory and practice within an Indigenous research paradigm

2018 ◽  
Vol 19 (4) ◽  
pp. 418-436 ◽  
Author(s):  
Michelle Pidgeon
Keyword(s):  
Higher Education ◽  
Indigenous Peoples ◽  
Paradigm Shift ◽  
Research Process ◽  
Theory And Practice ◽  
Indigenous Research ◽  
Research Paradigm ◽  
Research Projects ◽  
Practical Application ◽  
Indigenous Research Methodologies

There has been a paradigm shift amongst Indigenous peoples and researchers about how research with Indigenous peoples is conceived, implemented, and articulated. The result has been referred to as the Indigenous research paradigm (Wilson, 2003) and has taken the shape of Indigenous research methodologies and processes. The purpose of this article is to discuss the tenets of the Indigenous research paradigm in relation to its practical application within two research projects conducted in higher education settings in British Columbia, Canada. In sharing how these principles are lived during the research process, it discusses how each project embodied Indigenous research processes by being respectful, relevant, responsible, and reciprocal.

scholarly journals Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Dittmann ◽  
Paul Eisentraut ◽  
Caroline Goedecke ◽  
Yosri Wiesner ◽  
Martin Jekel ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Evolved Gas Analysis ◽  
Gas Analysis ◽  
Specific Adsorption ◽  
Adsorption Mechanisms ◽  
Adsorption Sites ◽  
Adsorption Processes ◽  
Inorganic Constituents

AbstractThe adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation.

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