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He was drawn to the antiquated platinum process for its long grayscale – its ability to display a seemingly infinite array of gradations between pure white and absolute black. The platinum process requires direct contact with the negative, without enlargement, so Penn first needed to create flawless negatives the same size as the desired print.
The platinum-group metals [a] (PGMs) are six noble, precious metallic elements clustered together in the periodic table. These elements are all transition metals in the d-block (groups 8, 9, and 10, periods 5 and 6). [1] The six platinum-group metals are ruthenium, rhodium, palladium, osmium, iridium, and platinum.
Ammonium hexachloroplatinate is used in platinum plating. Heating (NH 4) 2 [PtCl 6] under a stream of hydrogen at 200 °C produces platinum sponge. Treating this with chlorine gives H 2 [PtCl 6]. [2] Ammonium hexachloroplatinate decomposes to yield platinum sponge when heated to high temperatures: [2] [5] 3(NH 4) 2 PtCl 6 → 3Pt(s) + 2NH 4 Cl ...
Plating is a finishing process in which a metal is deposited on a surface. Plating has been done for hundreds of years; it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve solderability, to harden, to improve wearability, to reduce friction, to improve paint adhesion, to alter conductivity, to improve IR reflectivity, for ...
Platinum is a chemical element; it has symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish platina, a diminutive of plata "silver". [7] [8] Platinum is a member of the platinum group of elements and group 10 of the periodic table of ...
A process flow diagram (PFD) is a diagram commonly used in chemical and process engineering to indicate the general flow of plant processes and equipment. The PFD displays the relationship between major equipment of a plant facility and does not show minor details such as piping details and designations.
Process Flow Diagram A copy of the Process Flow, indicating all steps and sequence in the fabrication process, including incoming components. PFMEA A copy of the Process Failure Mode and Effect Analysis , reviewed and signed off by supplier and customer. The PFMEA follows the Process Flow steps, and indicates "what could go wrong" during the ...
The first structured method for documenting process flow, e.g., in flow shop scheduling, the flow process chart, was introduced by Frank and Lillian Gilbreth to members of ASME in 1921 as the presentation "Process Charts, First Steps in Finding the One Best Way to Do Work". [2]