Analysis of pore formation and development in carbon blacks activated in a CO2 gas atmosphere through microstructural observation

2021 ◽  
Author(s):  
Sang-Min Lee ◽  
Sang-Hye Lee ◽  
Suk-Hwan Kim ◽  
Jae-Seung Roh
Keyword(s):  
Pore Formation ◽  
Co2 Gas ◽  
Microstructural Observation ◽  
Carbon Blacks ◽  
Gas Atmosphere

scholarly journals PENGARUH SUHU AKTIVASI TERHADAP SIFAT FISIS DAN ELEKTROKIMIA ELEKTRODA SUPERKAPASITOR DARI LIMBAH DAUN AKASIA (Acacia mangium Wild)

2019 ◽  
Vol 16 (2) ◽  
pp. 81
Author(s):  
Kristin Natalia ◽  
Erman Taer
Keyword(s):  
Specific Capacitance ◽  
Acacia Mangium ◽  
Carbon Electrodes ◽  
Physical Activation ◽  
Carbon Electrode ◽  
Activation Temperature ◽  
Temperature Variations ◽  
Co2 Gas ◽  
Gas Atmosphere ◽  
Activating Agent

The carbon electrode from acacia leaves (Acacia mangium Wild) for supercapacitor cell has been fabricated with physical activation temperature variations of 800oC, 850oC, and 900oC for the AK800, AK850 and AK900 samples respectively. Carbon electrodes were carbonized at a temperature of 600oC followed by physical activation in CO2 gas atmosphere. The KOH is use as an activating agent. The results of physical properties characterization show the higher physical activation temperature cause lower density data and smaller pore size of the particles. The EDX data shows an increasing in the carbon content. The best specific capacitance was found in AK900 as high as 76 g F-1 and the lowest specific capacitance is found in AK800 as high as 12,4 g F-1. Specific capacitance increases with increasing physical activation temperature.

scholarly journals Influence of storage period on properties of biopolymer packaging materials and pouches

2017 ◽  
pp. 53-62 ◽  
Author(s):  
Sandra Bulut ◽  
Vera Lazic ◽  
Senka Popovic ◽  
Nevena Hromis ◽  
Danijela Suput
Keyword(s):  
Transmission Rate ◽  
Storage Period ◽  
Barrier Properties ◽  
Bilayer Film ◽  
Co2 Gas ◽  
Gas Atmosphere ◽  
Heat Seal ◽  
Seal Strength ◽  
Gas Transmission Rate

Bilayer biodegradable films based on pumpkin oil cake (PuOC) and zein, as well as pouches made from these materials, were prepared, and the changes of their mechanical, physicochemical and barrier properties were analyzed during four weeks of storage. Heat seal quality of formed pouches and composition of the gas atmosphere in the pouches were also monitored. The results showed that the bilayer film had a thickness of 300 ? 10 (?m), and no its changes were observed during the storage time. The tensile strength of the tested film increased slightly in the third week, but the elongation at break showed a decreasing trend during the whole storage period. The decreases in the moisture content, total soluble matter and swelling of the obtained film, were also observed. After one month of storage, the O2 transmission rate of tested films, increased from 27 to 64 (ml/m2 24h 1 bar), and the CO2 gas transmission rate from 147 to 188 (ml/m2 24h 1 bar). The heat seal strength of the PuOC/Zein pouches decreased during the whole storage period. The percentage of O2 in PuOC/Zein pouches increased up to 7 times during the storage period; however, the percentage of CO2 decreased up to 18 times already after one week, and then remained stable in the rest of the storage period. These results are, to a smaller extent, due to the gas transmission rate through the material, especially for CO2 , and to a greater extent, due to the low heat seal strength, which decreased through the storage period, and probably influenced the content of the gases in the pouches.

scholarly journals Samples of Ba1−xSrxCe0.9Y0.1O3−δ, 0 < x < 0.1, with Improved Chemical Stability in CO2-H2 Gas-Involving Atmospheres as Potential Electrolytes for a Proton Ceramic Fuel Cell

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1874
Author(s):  
Magdalena Dudek ◽  
Bartłomiej Lis ◽  
Radosław Lach ◽  
Salius Daugėla ◽  
Tomas Šalkus ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Grain Boundary ◽  
Chemical Stability ◽  
Chemical Resistance ◽  
Hydrogen Gas ◽  
Boundary Conductivity ◽  
Co2 Gas ◽  
Gas Atmosphere ◽  
Ceramic Fuel ◽  
Ceramic Fuel Cells

Comparative studies were performed on variations in the ABO3 perovskite structure, chemical stability in a CO2-H2 gas atmosphere, and electrical conductivity measurements in air, hydrogen, and humidity-involving gas atmospheres of monophase orthorhombic Ba1−xSrxCe0.9Y0.1O3−δ samples, where 0 < x < 0.1. The substitution of strontium with barium resulting in Ba1−xSrxCe0.9Y0.1O3−δ led to an increase in the specific free volume and global instability index when compared to BaCe0.9Y0.1O3−δ. Reductions in the tolerance factor and cell volume were found with increases in the value of x in Ba1−xSrxCe0.9Y0.1O3−δ. Based on the thermogravimetric studies performed for Ba1−xSrxCe0.9Y0.1O3−δ, where 0 < x < 0.1, it was found that modified samples of this type exhibited superior chemical resistance in a CO2 gas atmosphere when compared to BaCe0.9Y0.1O3−δ. The application of broadband impedance spectroscopy enabled the determination of the bulk and grain boundary conductivity of Ba1−xSrxCe0.9Y0.1O3−δ samples within the temperature range 25–730 °C. It was found that Ba0.98Sr0.02Ce0.9Y0.1O3−δ exhibited a slightly higher grain interior and grain boundary conductivity when compared to BaCe0.9Y0.1O3−δ. The Ba0.95Sr0.05Ce0.9Y0.1O3−δ sample also exhibited improved electrical conductivity in hydrogen gas atmospheres or atmospheres involving humidity. The greater chemical resistance of Ba1−xSrxCe0.9Y0.1O3−δ, where x = 0.02 or 0.05, in a CO2 gas atmosphere is desirable for application in proton ceramic fuel cells supplied by rich hydrogen processing gases.

Recent Progress In High-Resolution Shadowing For Biological Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 510-511 ◽  
Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann
Keyword(s):  
Heavy Metal ◽  
High Resolution ◽  
Freeze Drying ◽  
Atmospheric Conditions ◽  
Vacuum Equipment ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Gas Molecules ◽  
Residual Gas ◽  
Backing Layer

Freeze-drying followed by heavy metal shadowing is a long established and straight forward approach to routinely study the structure of dehydrated macromolecules. Very thin specimens such as isolated membranes or single macromolecules are directly adsorbed on C-coated grids. After rapid freezing the grids are transferred into a suitable vacuum equipment for freeze-drying and heavy metal shadowing.To improve the resolution power of shadowing films we introduced shadowing at very low specimen temperature (−250°C). To routinely do that without the danger of contamination we developed in collaboration with Balzers an UHV (p≤10-9 mbar) machine (BAF500K, Fig.2). It should be mentioned here that at −250°C the specimen surface acts as effective cryopump for practically all impinging residual gas molecules from the residual gas atmosphere.Common high resolution shadowing films (Pt/C, Ta/W) have to be protected from alterations due to air contact by a relatively thick C-backing layer, when transferred via atmospheric conditions into the TEM. Such an additional C-coat contributes disturbingly to the contrast at high resolution.

Simulation of SLF Interrupting Performance for CO2 Gas Circuit Breaker based on Serially Connected 3 Arc Models

2010 ◽  
Vol 130 (10) ◽  
pp. 888-894
Author(s):  
Tadashi Koshizuka ◽  
Keisuke Udagawa ◽  
Takeshi Shinkai ◽  
Toshiyuki Uchii ◽  
Hiromichi Kawano
Keyword(s):  
Circuit Breaker ◽  
Co2 Gas

Investigations of the corrosion activity of the KAlCl4 melts by the methods of physicochemical analysis

2019 ◽  
Vol 24 (4) ◽  
pp. 59-66
Author(s):  
E.S. Filatov
Keyword(s):  
Water Vapor ◽  
Hydrochloric Acid ◽  
Input Data ◽  
Corrosion Potential ◽  
Physicochemical Analysis ◽  
Metal Alloys ◽  
Corrosion Activity ◽  
Protection Efficiency ◽  
Gas Atmosphere ◽  
Metal Aluminum

Corrosion behavior of metal alloys in a melt of potassium chloroaluminate (KAlCl4) was investigated. Metal aluminum was used as a protector for protection against continuous frontal corrosion. The equilibrium potentials of aluminum and the corrosion potential of the alloys were measured. The data were obtained to evaluate the corrosion ability of the system of molten salt of potassium chloroaluminate - gas (argon) by measuring the redox potential of the specified environment depending on the composition of the gas atmosphere above it, i.e. from impurities of water vapor, hydrochloric acid, oxygen and other, for example, carbonaceous gases. The calculations of the protection efficiency using the potential difference between the metal aluminum and the protected material were performed. The regularities of changes in the equilibrium potentials of aluminum from the temperature and concentration were established as the fundamental data for possible use at determining the composition ratio of potassium chlorides and aluminum in potassium chloroaluminate as input data for the development of a sensor of composition of chloroaluminate potassium.

Dimerization of the Antimicrobial Peptide Polyphemusin I into One Polypeptide Chain: Theoretical and Practical Consequences

2019 ◽  
Vol 35 (5) ◽  
pp. 36-41
Author(s):  
V.A. Zenin ◽  
E.G. Sadykhov ◽  
A.N. Fedorov
Keyword(s):  
Antimicrobial Peptides ◽  
Pore Formation ◽  
Lipid Membrane ◽  
Polypeptide Chain ◽  
Unique Identifier ◽  
Bacterial Cultures ◽  
In Series ◽  
The Russian Federation ◽  
Peptide Dimerization ◽  
Putative Mechanism

A strategy of sequential dimerization of monomers of antimicrobial peptides (AMPs) into one polypeptide chain has been implemented on the example of a beta-structural AMP polyphemusin I which is one of the most effective candidate for use as an antibiotic. The possible polyphemusin I monomer and dimer structures in lipid membrane were studied in this work via molecular modeling. To this end, these molecules were chemically synthesized so that the dimer represented two monomers connected in series into one polypeptide chain with a flexible linker. The antimicrobial effects of monomer and dimer were then tested on various bacterial cultures, and their similarity was shown. Therefore, we can conclude that the pore formation is not a putative mechanism of the polyphemusin I action. antimicrobial peptides, peptide dimerization, mechanism of antimicrobial action, polyphemusin The work was supported by the Ministry of Science and Higher Education of the Russian Federation (Project Unique Identifier RFMEFI57517X0151).

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