All The Claims

1. A method for generating media playlists using a media guidance application, the method comprising:
determining a time period for presenting media to a user;
generating a first media playlist with a first play length corresponding to a length of time of the determined time period;
causing the first media playlist to be presented to the user;
processing a playback alteration operation while the first media playlist is presented to the user, wherein the playback alteration operation alters the first play length;
in response to completing the playback alteration operation, generating a second media playlist with a second play length corresponding to a length of time between a time associated with the completion of the playback alteration operation and an end time of the determined time period.
2. The method of claim 1, further comprising:
determining a content criterion; and
selecting a media asset to be presented during the first media playlist based on content associated with the media asset corresponding to the content criterion.
3. The method of claim 1, wherein generating the first media playlist comprises:
determining the length of time of the determined time period;
determining play lengths for each of a plurality of media assets; and
selecting a subset of the plurality of media assets, wherein a sum of the play lengths associated with each media asset in the subset corresponds to the length of time of the determined time period.
4. The method of claim 1, wherein generating the second media playlist comprises:
determining the length of time between the time associated with the completion of the playback alteration operation and the end time of the determined time period;
determining play lengths for each of a plurality of media assets; and
selecting a subset of the plurality of media assets, wherein a sum of the play lengths associated for each media asset in the subset corresponds to the length of time between the time associated with the completion of the playback alteration operation and the end time of the determined time period.
5. The method of claim 1, wherein the playback alteration operation includes a pause, fast-forward, rewind, skip, chapter selection, segment selection, skip segment, jump segment, next segment, previous segment, skip advertisement, next chapter, or previous chapter operation.
6. The method of claim 1, further comprising:
determining a media asset of the first media playlist that is being presented at the completion of the playback alteration operation; and
selecting the media asset for inclusion in the second media playlist.
7. The method of claim 6, wherein the media asset is presented before any other media asset in the second playlist.
8. The method of claim 1, further comprising:
determining whether a media asset of the first media playlist was not presented before the playback alteration operation was processed; and
selecting the media asset for inclusion in the second media playlist.
9. The method of claim 1, further comprising:
determining an order of media assets in the first media playlist that were not presented before the playback alteration operation was processed;
selecting the media assets for inclusion in the second media playlist in the order; and
adjusting the order based on the second play length.
10. The method of claim 1, wherein adjusting the order includes adding, removing, or cropping a media asset.
11. A system for generating media playlists using a media guidance application, the system further comprising control circuitry configured to:
determine a time period for presenting media to a user;
generate a first media playlist with a first play length corresponding to a length of time of the determined time period;
cause the first media playlist to be presented to the user;
process a playback alteration operation while the first media playlist is presented to the user, wherein the playback alteration operation alters the first play length;
in response to completing the playback alteration operation, generate a second media playlist with a second play length corresponding to a length of time between a time associated with the completion of the playback alteration operation and an end time of the determined time period.
12. The system of claim 11, wherein the control circuitry is further configured to:
determine a content criterion; and
select a media asset to be presented during the first media playlist based on content associated with the media asset corresponding to the content criterion.
13. The system of claim 11, wherein generating the first media playlist comprises:
determining the length of time of the determined time period;
determining play lengths for each of a plurality of media assets; and
selecting a subset of the plurality of media assets, wherein a sum of the play lengths associated with each media asset in the subset corresponds to the length of time of the determined time period.
14. The system of claim 11, wherein generating the second media playlist comprises:
determining the length of time between the time associated with the completion of the playback alteration operation and the end time of the determined time period;
determining play lengths for each of a plurality of media assets; and
selecting a subset of the plurality of media assets, wherein a sum of the play lengths associated for each media asset in the subset corresponds to the length of time between the time associated with the completion of the playback alteration operation and the end time of the determined time period.
15. The system of claim 11, wherein the playback alteration operation includes a pause, fast-forward, rewind, skip, chapter selection, segment selection, skip segment, jump segment, next segment, previous segment, skip advertisement, next chapter, or previous chapter operation.
16. The system of claim 11, wherein the control circuitry is further configured to:
determining a media asset of the first media playlist that is being presented at the completion of the playback alteration operation; and
selecting the media asset for inclusion in the second media playlist.
17. The system of claim 16, wherein the media asset is presented before any other media asset in the second playlist.
18. The system of claim 11, wherein the control circuitry is further configured to:
determining whether a media asset of the first media playlist was not presented before the playback alteration operation was processed; and
selecting the media asset for inclusion in the second media playlist.
19. The system of claim 11, wherein the control circuitry is further configured to:
determining an order of media assets in the first media playlist that were not presented before the playback alteration operation was processed;
selecting the media assets for inclusion in the second media playlist in the order; and
adjusting the order based on the second play length.
20. The system of claim 11, wherein adjusting the order includes adding, removing, or cropping a media asset.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A device for obtaining selective rigidity with respect to a patient, comprising:
a scaffold that is arranged to be flexible when in a first relaxed configuration, wherein the scaffold is configured to become substantially more rigid when a suction force is applied thereto, the scaffold comprising first and second opposing outer flexible layers that are sealed together to form a plurality of elongate pockets therein, and an expanded structure disposed within the plurality of elongate pockets and in communication with a vacuum port that receives the suction force.
2. The device of claim 1, wherein the expanded structure is configured to compress upon itself when in the presence of the suction force.
3. The device of claim 2, wherein the expanded structure compresses upon itself due to a substantial collapsing of a plurality of voids associated with the expanded structure.
4. The device of claim 1, wherein two or more pockets defining the plurality of elongate pockets are each in communication with each other and also in communication with the vacuum port such that the suction force communicates throughout the two or more pockets defining the plurality of pockets.
5. The device of claim 1, wherein the scaffold is disposed in a generally cylindrical configuration when fully expanded.
6. The device of claim 1, wherein the scaffold comprises a first closed end and a second open end, wherein the port is proximate to the second open end.
7. The device of claim 1, wherein the scaffold is disposed in a generally spherical configuration when fully expanded.
8. The device of claim 1, wherein the plurality of elongate pockets are oriented to define a plurality of windows formed from one or both of the first and second flexible layers disposed between the two or more of the plurality of elongate pockets.
9. The device of claim 8, wherein each of the plurality of windows are defined with the first and second layers sealed together.
10. The device of claim 8, wherein the plurality of windows are substantially transparent.
11. The device of claim 1, wherein the plurality of elongate pockets are aligned with respect each other to form a honeycomb structure along outer walls of the scaffold.
12. The device of claim 1, wherein the elongate pockets comprise a foam structure disposed therein.
13. The device of claim 12, wherein the foam structure is configured to substantially collapse upon itself when in communication with a suction force.
14. The device of claim 12, wherein the foam structure is defined from elongate strips of foam disposed within the plurality of pockets.
15. The device of claim 10, wherein the foam structure is defined from a plurality of foam pellets distributed within the plurality of pockets.
16. The device of claim 1, wherein the scaffold defines a retractor.
17. The device of claim 16, wherein the retractor is configured for use within the peritoneal cavity.
18. The device of claim 16, wherein the scaffold is defined to be deployable into a working area of a patient through a laparoscopic port, wherein the vacuum port extends out of the laparoscopic port.
19. The device of claim 1, wherein the scaffold defines a stent.
20. The device of claim 8, wherein one or more of the plurality of windows may be removed from the scaffold when the scaffold is in the relaxed configuration or the suction configuration.
21. The device of claim 1, wherein the scaffold is configured to rigidly support a portion of the anatomy.

1. An apparatus for controlling a selective catalytic reduction (SCR) system of an internal combustion engine system, comprising:
an ammonia storage module that determines an actual ammonia storage surface coverage on an SCR catalyst of the SCR system based on one of an excess ammonia flow rate entering an SCR catalyst and an excess NOx flow rate entering the SCR catalyst, wherein the excess ammonia flow rate, excess NOx flow rate, and actual ammonia storage surface coverage is determined without input from a NOx concentration sensor downstream of the SCR system, the ammonia storage module being further configured to determine an ammonia compensation value based on the actual ammonia storage surface coverage, the ammonia storage module comprising:
a mode determination module that determines the operating mode of the SCR system based on a pre-calibrated zero ammonia slip threshold as one of:
an ammonia adsorption mode when an ammoniaNOx ratio of exhaust gas entering the SCR catalyst is greater than the pre-calibrated zero ammonia slip threshold,
an ammonia desorption mode when the ammoniaNOx ratio is less than the pre-calibrated zero ammonia slip threshold, and
a neutral mode when the ammoniaNOx ratio is equal to the pre-calibrated zero ammonia slip threshold; and
a reductant dosing module that generates a reductant dosing command based on the ammonia compensation value;
wherein the ammonia storage module, reductant dosing module, and mode determination module each comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
2. An apparatus for controlling a selective catalytic reduction (SCR) system of an internal combustion engine system, comprising:
an ammonia storage module that determines an actual ammonia storage surface coverage on an SCR catalyst of the SCR system based on one of an excess ammonia flow rate entering an SCR catalyst and an excess NOx flow rate entering the SCR catalyst, wherein the excess ammonia flow rate, excess NOx flow rate, and actual ammonia storage surface coverage is determined without input from a NOx concentration sensor downstream of the SCR system, the ammonia storage module being further configured to determine an ammonia compensation value based on the actual ammonia storage surface coverage, the ammonia storage module comprising:
a mode determination module that determines the operating mode of the SCR system as one of an ammonia absorption mode, an ammonia desorption mode, and a neutral mode based on a pre-calibrated zero ammonia slip threshold, and
an excess ammonia flow rate module that determines the excess ammonia flow rate when the mode determination module determines the SCR system is operating in the adsorption mode;
wherein, when the mode determination module determines the SCR system is operating in the adsorption mode, the ammonia compensation value is at least partially based on the excess ammonia flow rate; and

a reductant dosing module that generates a reductant dosing command based on the ammonia compensation value;
wherein the ammonia storage module, reductant dosing module, mode determination module, and excess flow rate module comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
3. The apparatus of claim 2, wherein the ammonia storage module further comprises an ammonia adsorption mode module that estimates an actual ammonia storage surface coverage of the SCR catalyst based on the excess ammonia flow rate and a current temperature of the SCR catalyst, and wherein the ammonia adsorption mode module comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
4. The apparatus of claim 3, wherein the ammonia adsorption mode module comprises stored system dynamic adsorption time constant values relative to excess ammonia flow rates and SCR catalyst temperatures, the ammonia adsorption mode module estimating a rate of change of the actual ammonia storage surface coverage by comparing the excess ammonia flow rate and a current temperature of the SCR catalyst to the stored system dynamic time constant values, wherein the actual ammonia storage surface coverage is based on a mathematical integration of the estimated rate of change of the actual ammonia storage surface coverage.
5. The apparatus of claim 3, wherein the stored actual ammonia storage surface coverage values for SCR catalyst temperatures above high temperature threshold are approximately zero percent such that the estimated actual ammonia storage surface coverage is automatically reset following high exhaust temperature events.
6. The apparatus of claim 3, wherein:
the ammonia storage module further comprises an ammonia storage control module that determines the ammonia compensation value based on the estimated actual ammonia storage surface coverage and a predetermined ammonia storage surface coverage threshold;
the ammonia compensation value is negative if the estimated actual ammonia storage surface coverage is greater than the predetermined ammonia storage surface coverage threshold;
the ammonia compensation value is positive if the estimated actual ammonia storage surface coverage is less than the predetermined ammonia storage surface coverage threshold; and
wherein the ammonia storage control module comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
7. An apparatus for controlling a selective catalytic reduction (SCR) system of an internal combustion engine system, comprising:
an ammonia storage module that determines an actual ammonia storage surface coverage on an SCR catalyst of the SCR system based on one of an excess ammonia flow rate entering an SCR catalyst and an excess NOx flow rate entering the SCR catalyst, wherein the excess ammonia flow rate, excess NOx flow rate, and actual ammonia storage surface coverage is determined without input from a NOx concentration sensor downstream of the SCR system, the ammonia storage module being further configured to determine an ammonia compensation value based on the actual ammonia storage surface coverage, the ammonia storage module comprising:
an excess NOx flow rate module that determines the excess NOx flow rate when the mode determination module determines the SCR system is operating in the desorption mode;
wherein, when the mode determination module determines the SCR system is operating in the desorption mode, the ammonia compensation value being at least partially based on the excess NOx flow rate; and

a reductant dosing module that generates a reductant dosing command based on the ammonia compensation value;
wherein the ammonia storage module, reductant dosing module, mode determination module, and excess NOx flow rate module comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
8. The apparatus of claim 7, wherein the ammonia storage module further comprises an ammonia desorption mode module that estimates an actual ammonia storage surface coverage of the SCR catalyst based on the excess NOx flow rate and a current temperature of the SCR catalyst, wherein the ammonia desorption module comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
9. The apparatus of claim 8, wherein the ammonia desorption mode module comprises stored system dynamic desorption time constant values relative to excess NOx flow rates and SCR catalyst temperatures, the ammonia desorption mode module estimating a rate of change of the actual ammonia storage surface coverage by comparing the excess NOx flow rate and a current temperature of the SCR catalyst to the stored system dynamic time constant values, wherein the actual ammonia storage surface coverage is based on a mathematical integration of the estimated rate of change of the actual ammonia storage surface coverage.
10. The apparatus of claim 8, wherein:
the ammonia storage module further comprises an ammonia storage control module that determines the ammonia compensation value based on the estimated actual ammonia storage surface coverage and a predetermined ammonia storage surface coverage threshold;
the ammonia compensation value is negative if the estimated actual ammonia storage surface coverage is greater than the predetermined ammonia storage surface coverage threshold;
the ammonia compensation value is positive if the estimated actual ammonia storage surface coverage is less than the predetermined ammonia storage surface coverage threshold;
wherein the ammonia storage control module comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
11. An apparatus for controlling a selective catalytic reduction (SCR) system of an internal combustion engine system, comprising:
an ammonia storage module that determines an actual ammonia storage surface coverage on an SCR catalyst of the SCR system based on one of an excess ammonia flow rate entering an SCR catalyst and an excess NOx flow rate entering the SCR catalyst, wherein the excess ammonia flow rate, excess NOx flow rate, and actual ammonia storage surface coverage is determined without input from a NOx concentration sensor downstream of the SCR system, the ammonia storage module being further configured to determine an ammonia compensation value based on the actual ammonia storage surface coverage; and
a reductant dosing module that generates a reductant dosing command based on the ammonia compensation value;
wherein the ammonia storage module utilizes a feedforward model exclusively for determining the ammonia surface coverage and the ammonia compensation value;
wherein the ammonia storage module and reductant dosing module each comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
12. The apparatus of claim 1, wherein the ammonia compensation value comprises an ammonia compensation flow rate, the ammonia compensation flow rate being based on a difference between the determined actual ammonia storage surface coverage and a predetermined ammonia storage surface coverage threshold.
13. A selective catalytic reduction (SCR) system, comprising:
a reductant dosing system that doses reductant into an exhaust gas stream via a reductant doser;
an SCR catalyst that receives the exhaust gas stream and is positioned downstream of the reductant dosing system, wherein the SCR catalyst stores thereon ammonia present in the exhaust gas stream; and
a controller that controls a dosing rate of reductant dosed into the exhaust gas stream by the reductant dosing system based on an excess ammonia flow rate in the exhaust gas stream in an ammonia storage adsorption mode and an excess NOx flow rate in the exhaust gas stream in an ammonia storage desorption mode, wherein the controller determines an actual ammonia storage surface of the SCR catalyst based on one of the excess ammonia and excess NOx flow rates without input from a NOx sensor downstream from the SCR catalyst;
wherein the excess ammonia flow rate is based on the difference between an ammonia flow rate in the exhaust gas stream and the product of a NOx flow rate in the exhaust gas stream and a zero slip ammoniaNOx ratio;
wherein the excess NOx flow rate is based on the difference between a NOx flow rate in the exhaust gas stream and the product of an ammonia flow rate in the exhaust gas stream and the zero slip ammoniaNOx ratio;
wherein the controller comprises one or more of logic hardware and executable code, the executable code stored on one or more non-transitory machine-readable storage media.
14. The SCR system of claim 13, wherein:
the controller estimates all the actual ammonia storage surface coverage of the SCR catalyst based on the excess ammonia flow rate in the ammonia storage adsorption mode and the excess NOx flow rate in the ammonia storage desorption mode; and
the controller increases the dosing rate if the estimated actual ammonia storage surface coverage is less than a predetermined desired ammonia storage surface coverage threshold and decreases the dosing rate if the estimated actual ammonia storage surface coverage is more than the predetermined desired ammonia storage surface coverage threshold.
15. The SCR system of claim 14, wherein the desired ammonia storage surface coverage threshold is dependent on an age of the SCR catalyst.
16. A method for controlling a selective catalytic reduction (SCR) system of an internal combustion engine system, comprising:
determining a nominal reductant dosing rate for the SCR system;
determining an operating mode of the SCR system as one of:
an adsorption mode if an ammoniaNOx ratio in the exhaust gas stream is greater than a pre-calibrated zero slip ammoniaNOx ratio for a given SCR catalyst temperature, and
a desorption mode if the ammoniaNOx ratio in the exhaust gas stream is less than the pre-calibrated zero slip ammoniaNOx ratio for the given SCR catalyst temperature;

if the determined operating mode of the SCR system is the adsorption mode, estimating an actual ammonia storage surface coverage of the SCR system based on an excess ammonia flow rate in an exhaust gas stream flowing through the SCR system without input from a NOx sensor downstream from the SCR system;
if the determined operating mode of the SCR system is the desorption mode, estimating the actual ammonia storage surface coverage of the SCR system based on an excess NOx flow rate in the exhaust gas stream independently of the concentration of NOx in the exhaust gas stream downstream from the SCR system;
if the estimated actual ammonia storage surface coverage is greater than a desired ammonia storage surface coverage threshold, reducing the determined nominal reductant dosing rate;
if the estimated actual ammonia storage surface coverage is less than a desired ammonia storage surface coverage threshold, increasing the determined nominal reductant dosing rate; and
dosing reductant into the exhaust gas stream according to one of the reduced or increased nominal reductant dosing rates.
17. A method for controlling a selective catalytic reduction (SCR) system of an internal combustion engine system, comprising:
determining a nominal reductant dosing rate for the SCR system;
determining an operating mode of the SCR system as one of an adsorption and desorption mode;
if the determined operating mode of the SCR system is the adsorption mode, estimating an actual ammonia storage surface coverage of the SCR system based on an excess ammonia flow rate in an exhaust gas stream flowing through the SCR system without input from a NOx sensor downstream from the SCR system;
if the determined operating mode of the SCR system is the desorption mode, estimating the actual ammonia storage surface coverage of the SCR system based on an excess NOx flow rate in the exhaust gas stream independently of the concentration of NOx in the exhaust gas stream downstream from the SCR system;
if the estimated actual ammonia storage surface coverage is greater than a desired ammonia storage surface coverage threshold, reducing the determined nominal reductant dosing rate;
if the estimated actual ammonia storage surface coverage is less than a desired ammonia storage surface coverage threshold, increasing the determined nominal reductant dosing rate;
dosing reductant into the exhaust gas stream according to one of the reduced or increased nominal reductant dosing rates; and
automatically resetting the estimated ammonia storage surface area to zero to account for high exhaust temperature events by estimating the actual ammonia storage surface coverage of the SCR system.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A holder for a drill insert, the holder comprising:
a shank portion opposite a holder body portion;
the holder body portion comprising a generally cylindrical body having at least one axially extending chip evacuation flute;
the cutting portion further comprising a holder slot having a bottom seating surface over at least a portion of the holder slot and at least one attachment arm positioned on each side of the holder slot, wherein each attachment arm has at least one aperture formed therein; and
a clearance surface formed at the interface of the chip evacuation flute, the cylindrical surface of the body, and the bottom seating surface of the slot, wherein the clearance surface is adapted to direct chips into the axially extending chip evacuation flute.
2. The holder of claim 1, wherein the clearance surface extends axially from the bottom seating surface of the slot toward the shank for a distance greater than the width of the slot.
3. The holder of claim 1, wherein the clearance surface is formed as a planar surface transverse to the axis of the cylindrical body.
4. The holder of claim 1, wherein the clearance surface is formed at least in part as a groove.
5. The holder of claim 1, wherein the clearance surface extends from the chip evacuation groove toward the opposite slot wall a distance corresponding to at least one quarter of the slot width taken perpendicularly between the walls of the holder slot, said distance being perpendicular to the opposite slot wall.
6. The holder of claim 1, wherein the holder includes at least one flushing channel.
7. The holder of claim 1, wherein the chip evacuation flute is straight or helical.
8. A holder for a drill insert, the holder comprising:
a shank portion;
a body portion adjacent the shank portion;
at least one axially extending chip evacuation flute formed in the body portion;
a holder slot having a bottom seating surface and at least one attachment arm positioned on each side of the holder slot, wherein each attachment arm has at least one aperture formed therein;
a clearance surface formed at the interface of the chip evacuation flute, a cylindrical land surface of the body, and the bottom seating surface of the slot, wherein the clearance surface extends along the bottom seating surface of the slot from the chip evacuation flute toward and perpendicular to the opposing slot wall a distance corresponding to at least a quarter of the width of the holder slot taken perpendicular to the slot walls and the clearance surface axially extends from the bottom seating surface of the slot axially toward the shank portion.
9. The holder of claim 8, wherein the clearance surface is formed as a planar surface transverse to the axis of the cylindrical body.
10. The holder of claim 8, wherein the clearance surface is formed at least in part as a groove.
11. The holder of claim 8, wherein the clearance surface extends from the chip evacuation groove toward the opposite slot wall a distance corresponding to at least half of the slot width taken perpendicularly between the walls of the holder slot, said distance being perpendicular to the opposite slot wall.
12. The holder of claim 8, wherein the clearance surface extends from the chip evacuation groove toward the opposite slot wall a distance corresponding to at least two thirds of the slot width taken perpendicularly between the walls of the holder slot, said distance being perpendicular to the opposite slot wall.
13. The holder of claim 8, wherein the holder includes at least one flushing channel.
14. The holder of claim 8, wherein the chip evacuation flute is straight.
15. The holder of claim 8, wherein the chip evacuation flute is helical.
16. A drill tool assembly comprising: a drill holder body having a first end and a second end, wherein the second end comprises a shank portion adapted to be fixedly attached in a drilling machine, wherein the first end comprises a generally cylindrical body having at least one axially extending chip evacuation flute, a holder slot having a bottom seating surface over at least a portion of the holder slot and at least one attachment arm positioned on each side of the holder slot, wherein each attachment arm has at least one aperture formed therein, and a clearance surface formed at the interface of the chip evacuation flute, the cylindrical surface of the body, and the bottom seating surface of the slot; and
a drill insert body having a first end opposite a second end, a first face side opposite and parallel to a second face side, a pair of apertures formed through the face sides, and a first land side opposite a second land side, the first and second land sides formed between the ends and the face sides; and a margin formed on a portion of each land side, the margin having a leading side and a trailing side, wherein the leading side of each margin is formed as a helix and a helical flute is formed adjacent the leading side of each margin, wherein the helical flutes are formed radially outward of the apertures of the drill insert body;
wherein the first end of the drill insert body completely covers the bottom seating surface of the slot when the insert is attached to the holder.
17. The drilling tool assembly of claim 16, wherein the clearance surface is formed as a planar surface transverse to the axis of the cylindrical body of the holder.
18. The drilling tool assembly of claim 16, wherein the clearance surface is formed at least in part as curved surface.
19. The drilling tool assembly of claim 16, wherein the clearance surface extends from the chip evacuation groove toward the opposite slot wall a distance corresponding to at least a quarter of the slot width taken perpendicularly between the walls of the holder slot, said distance being perpendicular to the opposite slot wall.
20. The drilling tool assembly of claim 16, wherein the holder slot includes a locating boss extending from the bottom seating surface and the first end of the drill insert body has at least one recess which cooperates with the locating boss of the bottom seating surface to allow the insert to be seated against the bottom seating surface.