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Microoptics
Published in Christoph Gerhard, Optics Manufacturing, 2018
The volatile reaction products are thus gaseous silicon tetrafluoride (SiF4) and gaseous water (H2O). Decomposition of the network modifier sodium oxide (Na2O) as existent in a number of multicomponent glasses (compare Table 3.5) can be achieved using sulfuric acid (H2SO4), where sodium sulfate (Na2SO4) and water are formed in the course of the chemical reaction,
Parametric optimisation of plasma polishing process using response surface methodology
Published in Surface Engineering, 2023
Hari Narayan Singh Yadav, Manas Das
The principle of this process is controlled by the chemical interaction between the radicals, ions, species, and substrate surfaces while performing atomic-level material removal. The samples are prepared using grinding followed by the abrasive polishing method with Al2O3 as abrasive particles. The chemically driven plasma polishing generally improves the subsurface defects. During finishing, the process and reactive gases are admitted into the process chamber. The RF power is used to ionise the gases in the process chamber. The gases reach the excited state to produce high energy and high-density reactive fluorine radicals (F*), electrons, and ions, which finally generate ions, species, and reactive radicals, as shown in Figure 3(a,b). Then the produced reactive radicals interact with the substrate surface (i.e. Si atom) and generate silicon tetrafluoride (SiF4). The produced SiF4 is volatile and comes out of the plasma chamber without contaminating the substrate surface. Here MRR is obtained using a chemical reaction according to Eqs. (1) and (2) [23].
A Big Data Analytics-driven Lean Six Sigma framework for enhanced green performance: a case study of chemical company
Published in Production Planning & Control, 2023
Amine Belhadi, Sachin S. Kamble, Angappa Gunasekaran, Karim Zkik, Dileep Kumar M., Fatima Ezahra Touriki
During this reaction-filtration, fluoride is released as hydrofluoric acid HF, which in turn reacts with silica forming volatile gas silicon tetrafluoride SiF4 and hydrosoluble hexafluorosilicic acid H2SiF6. These harmful gases are mainly evacuated along with the wastewater (from the operations of gaseous waste scrubbing and phosphogypsum transportation) or released through the stacks.