Absorber hollow vessel wall
Hollow vertical enclosure with separate gas, solvent and access openings. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Absorber upper head
Hollow upper head with top gas passage; original schematic profile. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Absorber lower head
Hollow lower head with separate closed sump marker; original schematic profile. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower sump closure marker
Closed lower marker; no drain, pressure boundary fabrication or procedure. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Support skirt
Hollow raised support-location marker. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Skirt base ring
Annular base with actual anchor-location bores. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet hollow neck
Open sour-gas inlet boundary; no line design or selected connection. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet bored flange
Separate annular flange; hole pattern and class unspecified. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 1
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 2
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 3
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 4
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 5
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 6
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 7
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Sour-gas inlet joint smooth stud 8
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet hollow neck
Open lean-amine inlet boundary; no line design or selected connection. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet bored flange
Separate annular flange; hole pattern and class unspecified. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 1
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 2
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 3
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 4
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 5
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 6
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 7
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine inlet joint smooth stud 8
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet hollow neck
Open rich-amine outlet boundary; no line design or selected connection. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet bored flange
Separate annular flange; hole pattern and class unspecified. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 1
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 2
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 3
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 4
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 5
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 6
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 7
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Rich-amine outlet joint smooth stud 8
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Treated-gas outlet hollow neck
Open treated-gas outlet boundary; no line design or selected connection. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Treated-gas outlet bored flange
Separate annular flange; hole pattern and class unspecified. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower packed-zone retaining ring
Annular support-location ring beneath an open contacting zone. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower upper hold-down ring
Annular upper zone marker; no bed compression or restraint design. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 1 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 1 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 1 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 1 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 1 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 1 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 1 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 2 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 2 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 2 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 2 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 2 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 2 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 2 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 3 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 3 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 3 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 3 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 3 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 3 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 3 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 4 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 4 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 4 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 4 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 4 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 4 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lower open packing 4 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper packed-zone retaining ring
Annular support-location ring beneath an open contacting zone. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper upper hold-down ring
Annular upper zone marker; no bed compression or restraint design. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 1 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 1 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 1 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 1 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 1 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 1 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 1 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 2 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 2 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 2 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 2 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 2 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 2 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 2 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 3 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 3 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 3 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 3 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 3 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 3 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 3 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 4 slat 1
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 4 slat 2
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 4 slat 3
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 4 slat 4
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 4 slat 5
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 4 slat 6
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Upper open packing 4 slat 7
Separate open-lattice contacting marker, with clear spaces between members. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Lean-amine distributor ring
Open annular distributor-location marker above contacting zones. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 1
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 2
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 3
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 4
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 5
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 6
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 7
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Distributor spoke 8
Separate visual branch marker; not a metered liquid orifice or tested distributor. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Overhead mist-pad lattice 1
Separate overhead entrainment-control location marker; no removal efficiency. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Overhead mist-pad lattice 2
Separate overhead entrainment-control location marker; no removal efficiency. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Overhead mist-pad lattice 3
Separate overhead entrainment-control location marker; no removal efficiency. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Overhead mist-pad lattice 4
Separate overhead entrainment-control location marker; no removal efficiency. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Overhead mist-pad lattice 5
Separate overhead entrainment-control location marker; no removal efficiency. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Overhead mist-pad lattice 6
Separate overhead entrainment-control location marker; no removal efficiency. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway hollow neck
Access-boundary envelope with an actual hollow passage. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway bored flange
Separate drilled access flange with no rated closure. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway gasket location
Annular gasket location; no compression or seal evidence. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway cover
Solid closed cover; model reveal is no access permission or procedure. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 1
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 2
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 3
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 4
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 5
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 6
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 7
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
Closed manway joint smooth stud 8
Smooth illustrative stud; no threads or preload. Invented teaching proportions only; no hydraulic, mass-transfer, pressure, material, corrosion, emissions or service qualification.
