Modified Carbon Papers as Electrode Materials of all-Vanadium Redox Flow Battery

2013 ◽  
Vol 1492 ◽  
pp. 15-23
Author(s):  
Chih-Hsing Leu ◽  
Shu-Yuan Chuang ◽  
Kan-Lin Hsueh ◽  
Jia-Ming Huang ◽  
Chia-Chun Chung ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Binding Energy ◽  
Redox Reaction ◽  
Acid Treatment ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Vanadium Redox Flow Battery ◽  
Hydrolysis Reaction ◽  
Ozone Treatment ◽  
The Stability

ABSTRACTThe electrode materials for VRFB should possess higher electric conductivity, corrosion resistance and hydrophilic properties in sulfuric acid. The characteristics of the electrode materials affect the stability and the energy efficiency of VRFB. Carbon materials are the best suited for VRFB applications. In this study, the calcined treatment, acid treatment and ozone treatment were used to modify the surface of carbon papers. The redox reaction of [VO]2+/[VO2]+ on the modified carbon papers was evaluated by cyclic voltammetry (CV). The surface compositions of carbon materials were analyzed by X-ray photoelectron spectrometry (XPS). The experimental results reveal that three oxidative methods enhance the redox reaction of [VO]2+/[VO2]+. The calcined treatments and acid treatments also enhanced hydrolysis reaction. The mole ratio of O/C apparently increased, but the binding energy of C1s and O1s were not chemically shifted in the acid treatment. The intensity of binding energy of O1s, between 532 eV and 534 eV, apparently increased in the ozone and calcined treatments. The Ox treated samples were more hydrophilic than the Oz treated samples. In the Ox treated samples, the decrease of Rct value indicates that was contributed from the redox reaction of [VO]2+/[VO2]+ and hydrolysis reaction. It does not completely benefit the energy efficiency of VRFB. The 5 x 5 cm2 modified carbon papers were used as electrode materials in the VRFB. The voltage efficiency, coulomb efficiency and energy efficiency reached 93 %, 90 % and 83 %, respectively, at a current density of 12 mA．cm-2 at 0.8-1.8 V.

Destabilizing the Structural Integrity of SARS-CoV2 Receptor Proteins by Curcumin Along with Hydroxychloroquine: An Insilco Approach for a Combination Therapy

2020 ◽  
Author(s):  
Akhileshwar Srivastava ◽  
Divya Singh
Keyword(s):  
Binding Energy ◽  
Combination Therapy ◽  
Receptor Binding ◽  
Structural Integrity ◽  
Binding Domain ◽  
Receptor Binding Domain ◽  
Receptor Proteins ◽  
Main Protease ◽  
The Stability ◽  
Therapeutic Activities

Presently, an emerging disease (COVID-19) has been spreading across the world due to coronavirus (SARS-CoV2). For treatment of SARS-CoV2 infection, currently hydroxychloroquine has been suggested by researchers, but it has not been found enough effective against this virus. The present study based on in silico approaches was designed to enhance the therapeutic activities of hydroxychloroquine by using curcumin as an adjunct drug against SARS-CoV2 receptor proteins: main-protease and S1 receptor binding domain (RBD). The webserver (ANCHOR) showed the higher protein stability for both receptors with disordered score (<0.5). The molecular docking analysis revealed that the binding energy (-24.58 kcal/mol) of hydroxychloroquine was higher than curcumin (-20.47 kcal/mol) for receptor main-protease, whereas binding energy of curcumin (<a>-38.84</a> kcal/mol) had greater than hydroxychloroquine<a> (-35.87</a> kcal/mol) in case of S1 receptor binding domain. Therefore, this study suggested that the curcumin could be used as combination therapy along with hydroxychloroquine for disrupting the stability of SARS-CoV2 receptor proteins

scholarly journals Performance Evaluation of Heading-and-Winning Machines in the Conditions of Potash Mines

2021 ◽  
Vol 11 (8) ◽  
pp. 3444
Author(s):  
Sergey A. Lavrenko ◽  
Dmitriy I. Shishlyannikov
Keyword(s):  
Energy Efficiency ◽  
Experimental Studies ◽  
Efficiency Coefficient ◽  
Mechanized Method ◽  
Methodological Approaches ◽  
The Stability ◽  
Technical Solutions ◽  
Potash Mine ◽  
Complex Indicators ◽  
Potassium Magnesium

The authors focus on the process of potash ore production by a mechanized method. They show that currently there are no approved procedures for assessing the performance of heading-and-winning machines operating in the conditions of potash mines. This causes difficulties in determining the field of application of heading-and-winning machines, complicates the search for implicit technical solutions for the modernisation of existing models of mining units, prohibits real-time monitoring of the stability of stope-based technological processes and makes it difficult to assess the performance of the services concerning mining enterprises. The work represents an aggregate assessment of the performance of heading-and-winning machines for potash mines by determining complex indicators describing the technological and technical levels of organising the work in stopes. Such indicators are the coefficients of productivity and energy efficiency, respectively. Experimental studies have been carried out in the conditions of the potash mine of the Verkhnekamskoye potassium-magnesium salt deposit to assess the performance of the latest and most productive Ural-20R heading-and-winning machines manufactured in Russia. Using the above methodological approaches, this paper shows that the unsatisfactory technological performance of the studied machine is due to the low productivity of the mine district transport. The average productivity coefficient was 0.29. At the same time, high values of the energy efficiency coefficient show that the productivity of the machine is on par with design conditions.

The Photoluminescence Enhancement and Stability of Porous Silicon by Cathodic Reduction and Acid Treatment

2014 ◽  
Vol 887-888 ◽  
pp. 458-461
Author(s):  
Chang Qing Li ◽  
Kun Wang ◽  
Pei Jia Liu ◽  
Qi Ming
Keyword(s):  
Electron Microscope ◽  
Porous Silicon ◽  
Acid Treatment ◽  
Cathodic Reduction ◽  
Luminescence Properties ◽  
Sem Images ◽  
Photoluminescence Enhancement ◽  
The Stability ◽  
Scanning Electron ◽  
Cathode Reduction

Porous silicon (PSi) was fabricated by using electrochemical anodic etching method. Then acid treatment and cathode reduction treatment were employed to improve the luminescence properties and stability of PSi material. Photoluminescence (PL) measurements and scanning electron microscope (SEM) were used to observe the luminescence properties and microstructure of samples, respectively. The results of PL measurements showed that the PL intensity and the stability of luminescence of samples after cathodic reduction and acid treatment were significantly improved. The SEM images showed that the porosity of PSi may be increased through the cathodic reduction treated.

scholarly journals Calculation of nuclear energies and stability by the statistical method

1940 ◽  
Vol 174 (959) ◽  
pp. 523-545 ◽  
Keyword(s):  
Statistical Theory ◽  
Binding Energy ◽  
Statistical Method ◽  
Atomic Number ◽  
Quantum States ◽  
Hartree Approximation ◽  
Stable Nucleus ◽  
The Stability

Leaving out of consideration those nuclei of small atomic number it is possible to develop a statistical theory of nuclei. Bethe and Bacher (1936, p. 149), as well as many other writers, have treated this subject in great detail starting from the Hartree approximation. All these investigations were mainly concerned with the binding energy, and not much attention has been paid so far to the stability of nuclei according to the statistical theory, except the determination of the most stable nucleus with a given atomic number: this is due to the fact that previous investigators have always neglected to distinguish between quantum states with opposite spin, thereby losing the distinction between “odd” and “even” nuclei, which is essential for stability considerations.

Cellulose Nanofibers Derived Carbon Aerogel with 3D Multiscale Pore Architecture for High-Performance Supercapacitors

Nanoscale ◽  
2021 ◽  
Author(s):  
Lumin Chen ◽  
Hou-Yong Yu ◽  
Ziheng Li ◽  
Xiang Chen ◽  
Wenlong Zhou
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Cellulose Nanofibers ◽  
Rate Capability ◽  
Carbon Aerogel ◽  
Large Specific Surface Area ◽  
Hierarchical Porous Structure ◽  
Pore Architecture ◽  
Hierarchical Porous

Carbon materials are highly promising electrode materials for supercapacitors, due to their hierarchical porous structure and large specific surface area. However, the limited specific capacitance and inferior rate capability significantly...

Electrochemical lithium recovery with lithium iron phosphate: What causes performance degradation and how can we improve the stability?

2021 ◽  
Author(s):  
Lei Wang ◽  
Kathleen C Frisella ◽  
Pattarachai Srimuk ◽  
Oliver Janka ◽  
Guido Kickelbick ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Manganese Oxide ◽  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
High Energy ◽  
Performance Degradation ◽  
Electrochemical Processes ◽  
High Energy Efficiency ◽  
The Stability

Electrochemical processes enable fast lithium extraction, for example, from brines, with high energy efficiency and stability. Lithium iron phosphate (LiFePO4) and manganese oxide (λ-MnO2) have usually been employed as the...

High Energy Efficiency With Low-Pressure Drop Configuration for an All-Vanadium Redox Flow Battery

2016 ◽  
Vol 13 (4) ◽  
Author(s):  
S. Kumar ◽  
S. Jayanti
Keyword(s):  
Energy Efficiency ◽  
Pressure Drop ◽  
Flow Field ◽  
Peak Power ◽  
Low Pressure ◽  
Vanadium Redox Flow Battery ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Electrolyte Circulation ◽  
Vanadium Redox

In this paper, we present experimental studies of electrochemical performance of an all-vanadium redox flow battery cell employing an active area of 103 cm2, activated carbon felt, and a novel flow field, which ensures good electrolyte circulation at low pressure drops. Extended testing over 151 consecutive charge/discharge cycles has shown steady performance with an energy efficiency of 84% and capacity fade of only 0.26% per cycle. Peak power density of 193 mW cm−2 has been obtained at an electrolyte circulation rate of 114 ml min−1, which corresponds to stoichiometric factor of 4.6. The present configuration of the cell shows 20% improved in peak power and 30% reduction in pressure drop when compared to a similar cell with a different electrode and a serpentine flow field.

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