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The proton-exchange membrane is commonly made of materials such as perfluorosulfonic acid (PFSA, sold commercially as Nafion and Aquivion), which minimize gas crossover and short circuiting of the fuel cell. A disadvantage of fluor containing polymers is the fact that during production (and disposal) PFAS products are formed.
A proton-exchange membrane, or polymer-electrolyte membrane (PEM), is a semipermeable membrane generally made from ionomers and designed to conduct protons while acting as an electronic insulator and reactant barrier, e.g. to oxygen and hydrogen gas. [1]
Fuel gas, such as natural gas, undiluted liquefied petroleum gases (vapor phase only), liquefied petroleum gas–air mixtures, or mixtures of these gases. Liquefied petroleum gases (LPG) as used in this standard, shall mean and include any material which is composed predominantly of any of the following hydrocarbons , or mixtures of them ...
As is the case for other archaea, methanogens lack peptidoglycan, a polymer that is found in the cell walls of bacteria. [15] Instead, some methanogens have a cell wall formed by pseudopeptidoglycan (also known as pseudomurein). Other methanogens have a paracrystalline protein array (S-layer) that fits together like a jigsaw puzzle. [5]
This component functions much like peptidoglycan in a bacterial cell. [7] Pseudopeptidoglycan is used by the archaeal cell to determine its shape and provide structure to the cell. It is also used to protect the cell from undesired molecules or anything harmful in its environment.
A protonic ceramic fuel cell or PCFC is a fuel cell based around a ceramic, solid, electrolyte material as the proton conductor from anode to cathode. [1] These fuel cells produce electricity by removing an electron from a hydrogen atom, pushing the charged hydrogen atom through the ceramic membrane, and returning the electron to the hydrogen ...
In chemistry, a precursor is a compound that participates in a chemical reaction that produces another compound. In biochemistry , the term "precursor" often refers more specifically to a chemical compound preceding another in a metabolic pathway , such as a protein precursor .
Stage two occurs in the cytoplasmic membrane. It is in the membrane where a lipid carrier called bactoprenol carries peptidoglycan precursors through the cell membrane. Undecaprenyl phosphate will attack the UDP-MurNAc penta, creating a PP-MurNac penta, which is now a lipid . [20] EC 2.7.8.13 by MraY. [21]