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Harry Diamond Laboratories

Harry Diamond Laboratories
Adelphi, Maryland in the United States
HDL building.
The Harry Diamond Laboratories building complex, which now houses the headquarters of the U.S. Army Research Laboratory.
HDL emblem.
Harry Diamond Laboratories emblem.
TypeMilitary research laboratory
Site information
OwnerDepartment of Defense
OperatorU.S. Army
Controlled byArmy Materiel Command
ConditionRedeveloped as part of the U.S. Army Research Laboratory
Site history
Built1949 (as Harry Diamond Ordnance Laboratory)

The Harry Diamond Laboratories (HDL) was a research facility under the National Bureau of Standards (NBS) and later the U.S. Army. It conducted research and development in electronic components and devices and was at one point the largest electronics research and development laboratory in the U.S. Army. HDL also acted as the Army’s lead laboratory in nuclear survivability studies and operated the Aurora Pulsed Radiation Simulator, the world’s largest full-threat gamma radiation simulator. In 1992, HDL was disestablished, and its mission, personnel, and facilities were incorporated into the newly created U.S. Army Research Laboratory (ARL). As part of this transition, the Army designated the HDL building as the site of ARL’s new headquarters.[1][2]

The installation was named in honor of pioneer radio engineer and inventor Harry Diamond, who led the Ordnance Development Division during World War II. Diamond contributed greatly to the fundamental concept and design of proximity fuzes.[1]

History

Under the National Bureau of Standards

The origins of the Harry Diamond Laboratories trace back to the development of the radio proximity fuze at the National Bureau of Standards (NBS). During the 1930s, British military researchers investigated the feasibility of a proximity fuze, a device that would detonate an explosive charge only when it approached the immediate vicinity of its target. At the time, conventional artillery and antiaircraft shells very rarely hit their target, especially a moving one, because their detonation either required direct contact or relied on accurate predictions with an altimeter or a timer set at launch.[3][4]

In 1939, British researchers William Butement, Edward Shire, and Amherst Thomson at the Air Defense Experimental Establishment conceived of a proximity fuze that used radio waves to sense the proximity of the target.[5][6][7] While Butement and his team were able to construct and crudely test a prototype fuze in 1940, the high production demands of World War II ultimately stalled its development.[6][8] As a result, the British decided to share their research on the project with the United States in hopes that the U.S. could complete the technology. In September 1940, Sir John Cockcroft delivered all available information about the radio proximity fuze to the newly formed National Defense Research Committee (NDRC) as part of the Tizard Mission.[5][6] The chairman of NDRC, Vannevar Bush, appointed Merle Tuve, the director of the Department of Terrestrial Magnetism at the Carnegie Institution for Science, to lead the U.S. research on proximity fuzes.[4][9]

Harry Diamond and Alexander Ellett showcasing the proximity fuze.
Harry Diamond (left) and Alexander Ellett (right) with examples of their proximity fuze.

By November 1940, Tuve recognized that two types of radio proximity fuzes were needed: one for rotating projectiles and one for non-rotating projectiles. The former was sought by the U.S. Navy for anti-aircraft guns, while the latter was best suited for U.S. Army and U.S. Air Force weapons such as bombs, rockets, and mortars.[3][8] The team headed by Tuve at the Carnegie Institution, which later moved to the Applied Physics Laboratory at Johns Hopkins University in 1942, took on the development of the radio proximity fuze for rotating projectiles.[3][4] Meanwhile, the development of the radio proximity fuze for non-rotating projectiles was assigned to Harry Diamond and Wilford Hinman Jr. at the NBS and overseen by Alexander Ellett of NDRC.[3][6][10]

Diamond, who was the chief of NBS’s radio and photoelectric fuze groups, determined that utilizing the Doppler effect would provide the best results for a proximity fuze in a non-rotating projectile. Diamond and Hinman subsequently developed a diode detector system that activated when the amplitude of the reflected radio waves exceeded a predetermined value. In April and May 1941, Diamond’s group tested a series of crude box models based on this principle in successful bomb drops against water targets. While only a third of the models functioned properly during the tests, the experiment demonstrated that Diamond and Hinman’s idea had potential. Diamond and his team spent the next several months working on the fuze’s electronic circuits and safety mechanisms.[3][6][10]

Army officials unveil a large plaque on a building that reads “Harry Diamond Ordnance Laboratory” with the text “Erected by the Corps of Engineers 1945 Dedicated 1949” underneath.
Dedication of the Harry Diamond Ordnance Laboratory in 1949.

In May 1942, the U.S. Army made its first urgent request for a proximity fuze for the new 4.5-inch airborne rocket against the German Luftwaffe. Once the dimensions for the fuze were decided, Diamond’s team completed the fuze design in 2 days. After testing was conducted in June 1942, NBS constructed more than a thousand fuzes based on this design using the small-scale production lines in its model shops. The U.S. Army later produced almost 400,000 of NBS’s fuzes in 1943 and an additional 400,000 were made before the end of the war. Due to the expansion of fuze-related activities at NBS, the Bureau established the Ordnance Development Division in December 1942. The new division initially consisted of 200 people working on proximity fuzes for rockets and bombs with Diamond acting as the division chief. By the end of the war, the size of the division had doubled.[3][10]

After the war, a large laboratory complex designed to house the Bureau’s Ordnance Development Division, Ordnance Electronics Division, and Electromechanical Division was established in 1946.[3][11][12] Meanwhile, Diamond continued to lead the Ordnance Development Division until his death in 1948.[1] In honor of his work, the laboratory complex was renamed to the Harry Diamond Ordnance Laboratory in 1949.[3][12]

Under the U.S. Army

NBS underwent significant restructuring and downsizing in the years following World War II. During this time period, several wartime programs managed by the Bureau were relocated elsewhere.[13] One of the major causes of this organizational change was a congressional report by the Kelly Committee following the AD-X2 battery additive controversy during the early 1950s. The Kelly Committee, which was formed by the NBS Visiting Committee and the National Academy of Sciences at the request of Commerce Secretary Charles Sinclair Weeks, advised NBS to return to non-military research and testing and transfer its weapons programs to the Department of Defense.[3][14][15]

As part of the transition, the majority of the Harry Diamond Ordnance Laboratory was transferred to the U.S. Army in September 1953 and renamed the Diamond Ordnance Fuze Laboratory (DOFL). Despite the change in command, however, the laboratory’s operations remained at the original building complex in Washington, D.C. Hinman Jr., who had succeeded Diamond as the head of the program after Diamond’s death, became DOFL’s first technical director after it moved to the Army.[12][15]

As an element of the Army’s Ordnance Corps, DOFL focused its research and development efforts on proximity fuzes and other related items. Areas that received attention included printed circuits, microminiaturization, casting resins, flow and temperature measuring systems, reserve power supplies, high-resolution radar, air navigation systems, and telemetering equipment. DOFL was also responsible for determining the susceptibility of ordnance electronics materiel to nuclear radiation and investigating methods of radiation hardening.[16] When the U.S. Army Materiel Command (AMC) was established during the 1962 Army reorganization, DOFL was assigned directly to AMC as a corporate laboratory. The following year, DOFL had its name officially changed to the Harry Diamond Laboratories (HDL).[1][17]

During the 1960s, the U.S. Army made plans to relocate HDL after a joint Army and Navy study group recommended that the laboratory be moved to a 137-acre site adjacent to the U.S. Naval Ordnance Laboratory in Adelphi, Maryland.[18] Consisting mostly of undeveloped farmland, the site was acquired by the U.S. Army in 1969, and construction of HDL’s new facilities began shortly afterwards.[19] In July 1971, HDL also acquired AMC’s Woodbridge Research Facility along with roughly 642 acres of land in Woodbridge, Virginia to use as a satellite site. Initiated in May 1970, this acquisition was a move by the Army to consolidate AMC’s nuclear weapons effects research and test activities. As a result, the U.S. Army Mobility Equipment Research and Development Command’s Electromagnetic Effects Laboratory was relocated from Fort Belvoir Engineer Proving Ground to Woodbridge in September 1971. As a satellite facility of HDL, the Woodbridge Research Facility primarily conducted investigations into the simulated effects of electromagnetic pulses generated by nuclear detonation on electronic systems. Following the cessation of nuclear detonation testing, the simulations produced by the facility enabled the Army to test the vulnerability of tactical systems to the effects of nuclear attack and gather data for the development of hardening techniques.[18][20]

In 1973, operations at HDL were officially moved from Washington, D.C. at Connecticut Ave. and Van Ness St. to the newly constructed research complex in Adelphi, Maryland.[12] HDL employees were moved to Adelphi as part of a three-phase relocation program as different sections of the facility underwent construction. In November 1973, about 500 of the total employees were moved to the H-shaped Adelphi complex. The second phase took place in 1974 with about 400 employees, and the remaining 500 workers were moved in the fall of 1975.[17][21] In 1980, the Army acquired the Blossom Point Field Test Facility in Charles County, Maryland, and assigned it to HDL as its second satellite installation. Consisting of 20 buildings, the Blossom Point facility was used by HDL to conduct field tests on HDL-developed fuzes, explosive and pyrotechnic devices, and electronic telemetry systems. Construction of HDL’s Adelphi complex reached completion in 1983, by which point the site housed a total of 22 structures.[18]

In 1992, HDL was among the seven Army laboratories that were consolidated to form the U.S. Army Research Laboratory (ARL) following the Base Realignment and Closure (BRAC) commission in 1991. In addition, the Adelphi research complex was renamed the Adelphi Laboratory Center and became the headquarters for ARL.[20][22] While HDL’s Blossom Point satellite facility was transferred under ARL, the Woodbridge satellite facility was ultimately closed.[20][23]

Research

Aurora Pulsed Radiation Simulator.png
The Aurora Pulsed Radiation Simulator, the first gamma radiation simulator of its size and capacity built in the world, was in operation from 1971 to 1996.

At its inception, the Harry Diamond Ordnance Laboratory was originally established to further advance U.S. research and development in electronic fuzing for rockets, mortars, artillery, and missiles. Over time, the laboratory’s principal activities expanded significantly to include other ordnance specialties such as radar technology, integrated circuits, nuclear survivability, and basic research in the physical sciences. By the 1980s, the Harry Diamond Laboratories was the largest electronics R&D laboratory in the U.S. Army and represented the Army’s lead laboratory for the study of nuclear effects.[1][2] Since 1971, the facility housed and operated the Aurora Pulsed Radiation Simulator, which was the world’s largest gamma radiation simulator at the time. Before it was decommissioned and disassembled in 1996, the Aurora Simulator had conducted a total of 287 numbered tests.[24] HDL also operated the Army’s largest facility for designing, fabricating, and testing integrated circuits.[2]

HDL consisted of four specialized laboratories, each headed by its own director: the Advanced Research Laboratory, the Systems Research Laboratory, the Research and Development Laboratory, and the Components Research Laboratory. The Advanced Research Laboratory specialized in exploratory systems, special components, optical systems, and physical research. The Systems Research Laboratory specialized in radio systems, nuclear vulnerability and countermeasures, microwave components, systems feasibility, fluid amplifiers, applied physics, and computation and analysis. The Research and Development Laboratory specialized in projectile fuzes, missile fuzes, and heavy artillery fuzes as well as limited warfare weapons, electronic timers, safety devices, parachute opening devices, fluid systems, large radar systems, telemetry, air defense, and missile trajectory measuring systems. Lastly, the Components Research Laboratory specialized in materials and techniques, microminiaturization, tubes, and power supplies. The technologies developed by these laboratories, if applicable, would be prepared for mass production by HDL’s Engineering Division, which was responsible for quality assurance, test engineering, value analysis, and industrial support.[25]

Projects

Fuzes.

As an early authority on electronic fuze technology, the Harry Diamond Laboratories contributed to the development of not only the proximity fuze but many other fuze systems including the following:

HDL also designed and developed fuzes for the following missiles:[25]

HDL either led or was involved in the development of numerous technologies, including the following:

  • Automatic step-and-repeat camera: A device used in photolithography to manufacture integrated circuits; also known as a stepper. HDL developed the first stepper that was completely automatic.[53]
  • Fluidics: The use of the physical properties of liquids or gases to perform analog or digital operations. The science of fluid amplification began at HDL. HDL applications of fluid amplification include the Army Artificial Heart Pump and the Army Emergency Respirator.[25][54][55]
  • High-Spin Tabletop Artillery Simulator: A device used to test fuze power supplies, such as that of the M732 fuze, by simulating the forces in an artillery tube.[56][57]
  • Lunar penetrometer: A tool used to measure the load-bearing characteristics of the moon in preparation for spacecraft landings. HDL developed the omnidirectional accelerometer for the lunar penetrometer.[25][58]
  • M1A1 Abrams tank: A main battle tank of the U.S. Army. HDL developed an auxiliary power unit for the M1A1 tank to extend the tank’s battery life.[50]
  • Photolithography: The process of using light to etch circuit patterns on light-sensitive substrates for integrated circuit manufacturing.[59]
  • Tactical nuclear slide rule: A tool used to calculate the blast effects and damage resulting from detonating a nuclear weapon.[60][61]
  • W48: A nuclear artillery shell that can be fired from any standard 155-mm howitzer. HDL contributed to its design and development alongside Picatinny Arsenal, Frankford Arsenal, and the U.S. Army Materials Research Agency.[62]

See also

References

  1. ^ a b c d e U.S. Army Research Laboratory (September 2017). History of the U.S. Army Research Laboratory. Government Printing Office. ISBN 978-0-16-094231-0.
  2. ^ a b c "Army Materiel Command Labs and RDE Centers". Army RD&A Magazine. Vol. 27, no. 4. July–August 1986. pp. 1–10.
  3. ^ a b c d e f g h i Cochrane, Rexmond (1974). Measures for Progress: A History of the National Bureau of Standards (PDF) (2nd ed.). U.S. Department of Commerce, National Bureau of Standards.
  4. ^ a b c Stubblebine, David (July 2021). "VT Radio Proximity Munitions Fuze". World War II Database.
  5. ^ a b Burns, R.W. (1993). "Early history of the proximity fuze (1937-1940)". IEE Proceedings A - Science, Measurement and Technology. 140 (3): 224–236. doi:10.1049/ip-a-3.1993.0035. ISSN 2054-0337 – via IET Digital Library.
  6. ^ a b c d e Brennan, James (September 1968). "The Proximity Fuze: Whose Brainchild?". U.S. Naval Institute Proceedings. 94 (9): 787 – via U.S. Naval Institute.
  7. ^ Robinson, Ray. "W.A.S. Butement (1904-1990)". Tube Radio Australia.
  8. ^ a b Brown, Louis (July 1993). "The proximity fuze". IEEE Aerospace and Electronic Systems Magazine. 8 (7): 3–10. doi:10.1109/62.223933 – via IEEE Xplore.
  9. ^ Allen, Kevin (2011). "The Proximity Fuse: The Gunner's Dream Finally Became Realized". Warfare History Network. Vol. 12, no. 4.
  10. ^ a b c Arora, Shri (2010). Proximity Fuzes: Theory and Techniques. Defence Scientific Information and Documentation Centre. ISBN 9788186514290.
  11. ^ Schooley, Jim (8 November 2018). "NBS Moves West". National Institute of Standards and Technology.
  12. ^ a b c d Passaglia, Elio (1999). A Unique Institution: The National Bureau of Standards, 1950-1969 (PDF). U.S. Department of Commerce, Technology Administration, National Institute of Standards and Technology.
  13. ^ Friday, Dennis (May 2001). "Radio-Frequency Metrology from NBS to NIST: The Legacy". IEEE Electromagnetic Compatability Society Newsletter.
  14. ^ Inglis-Arkell, Esther (25 August 2014). "This Classic Science-Denying Scandal Shows Why Too Much Testing Is Bad". Gizmodo.
  15. ^ a b Lyons, John; Brown, E.A.; Fonoroff, B. (2001). "Radio Proximity Fuzes". In Lide, David (ed.). A Century of Excellence in Measurements, Standards, and Technology: A Chronicle of Selected NBS/NIST Publications, 1901-2000. National Institute of Standards and Technology, Special Publication 958. pp. 59–62.
  16. ^ "DOFL Noted for Key Role in Defense R&D". Army Research and Development Newsmagazine. Vol. 2, no. 1. January 1961. p. 3.
  17. ^ a b c "HDL Marks 20th Anniversary, Looks to Move Into $42.8 Million Complex". Army Research and Development News Magazine. Vol. 14, no. 5. 1973. pp. 16–19.
  18. ^ a b c National Park Service & Building Technology Incorporated (July 1984). Historic Properties Report: Harry Diamond Laboratories, Maryland and Satellite Installations, Woodbridge Research Facility, Virginia and Blossom Point Field Test Facility, Maryland (PDF) (Report). Report No. AD-A175872 – via Defense Technical Information Center.
  19. ^ Adelphi Laboratory Center (PDF) (Report). Maryland Department of the Environment. March 1998.
  20. ^ a b c Waltemyer, T.A. (5 August 1992). A Compilation of Historical Notes Regarding the Woodbridge Research Facility (PDF) (Report).
  21. ^ "'A Great Day in a Proud Tradition'...Secretary of Army Callaway Pays Tribute to HDL's R&D Contributions to Defense". Army Research and Development News Magazine. Vol. 15, no. 1. January–February 1974. p. 14.
  22. ^ Moye, William (May 1997). The Genealogy of ARL (Report). U.S. Department of the Army. Report No. AD-A383226 – via Defense Technical Information Center.
  23. ^ "Blossom Point". GlobalSecurity.org. 7 May 2011.
  24. ^ Historic American Engineering Record. Aurora Pulsed Radiation Simulator (Report). National Park Service. Report No. MD-144 – via Library of Congress.
  25. ^ a b c d e f g Harry Diamond Laboratories. U.S. Army Materiel Command. 1965.
  26. ^ Kinzelman, Gerald (30 July 1959). Cigarette Fuze Field Test (PDF) (Report). Diamond Ordnance Fuze Laboratories. Report No. AD0313258.
  27. ^ "Two More DOFL Inventors". Civil Service Journal. 3 (2): 10. October–December 1962.
  28. ^ a b c Doctor, N. (30 June 1960). Progress in Miniaturization and Microminiaturization (PDF) (Report). Diamond Ordnance Fuze Laboratories. Report No. AD0319561 – via Defense Technical Information Center.
  29. ^ Moore, Warren (14 October 1960). "T320-Type (Firefly) Fuzes". U.S. Government Research Reports. 34 (4): 436.
  30. ^ Miazza, John (May 1974). Design and Development of FZU-32/B Bomb Fuze Initiator (PDF) (Report). Air Force Armament Laboratory. Report No. AFATL-TR-74-88 – via Defense Technical Information Center.
  31. ^ Bertin, John; Goodyear, Richard (18 June 1982). Multiple Launch Rocket System (MLRS) Fuze (PDF) (Report). U.S. Military Academy. Report No. AD-A117395 – via Defense Technical Information Center.
  32. ^ Campagnuolo, Carl (July 1983). Fluidic Generator to Power Rocket Proximity Fuze (PDF) (Report). Harry Diamond Laboratories. Report No. HDL-TM-83-11 – via Defense Technical Information Center.
  33. ^ Goodyear, Richard; Lee, Henry (February 1981). Performance of the Fluidic Power Supply for the XM445 Fuze in Supersonic Wind Tunnels (PDF) (Report). Harry Diamond Laboratories. Report. No. AD-A097625 – via Defense Technical Information Center.
  34. ^ Richmond, Louis (30 October 1963). Summary Report: Fuze, PIBD, T278E8 (PDF) (Report). Harry Diamond Laboratories. Report No. AD0429314 – via Defense Technical Information Center.
  35. ^ Lindner, Victor (November–December 1964). "The New Ammunition". Ordnance. 49 (267): 294–297. JSTOR 45361285 – via JSTOR.
  36. ^ Army Ammunition Data Sheets for Land Mines (FSC 1345) (PDF) (Report). Department of the Army. 14 April 2000.
  37. ^ Campagnuolo, Carl; Fine, Jonathan (July 1983). Present Capability of Ram Air-Driven Alternators Developed at HDL as Fuze Powers Supplies (PDF) (Report). Harry Diamond Laboratories. Report No. HDL-TR-2013 – via Defense Technical Information Center.
  38. ^ Parsons, A.N. (27 September 1954). Notes on the Operation and Installation of the Sparrow II Missile (Report). Avro Canada. Report No. C105-R-0003.
  39. ^ "History of the MK.54 Warhead".
  40. ^ McMullen, Richard. History of Air Defense Weapons 1946-1962. HQ Air Defense Command.
  41. ^ Taylor, R.E. (31 July 1956). Fuze, Guided Missile, Proximity, T3008E5 Design and Performance (PDF) (Report). Diamond Ordnance Fuze Laboratories. Report No. AD0307706 – via Defense Technical Information Center.
  42. ^ Parsch, Andreas (2003). "JPL/Firestone SSM-A-17/M2/MGM-5 Corporal". Directory of U.S. Military Rockets and Missiles.
  43. ^ "New Technical Director Advanced as DOFL Progressed" (PDF). Army Research and Development Newsmagazine. Vol. 3, no. 5. May 1962. p. 6.
  44. ^ "Awards". Army Research and Development News Magazine. Vol. 14, no. 3. May–June 1973. p. 29.
  45. ^ Pollin, Irvin (August 1973). Precision Transonic Barometric Fuze System for the Laser Guided Honest John Missile (PDF) (Report). Harry Diamond Laboratories. Report No. HDL-TR-1646 – via Defense Technical Information Center.
  46. ^ Rotkin, Israel (4 August 1959). Summary of Microminiaturization Program – FY 1959 (PDF) (Report). Diamond Ordnance Fuze Laboratories. Report No. AD0312162 – via Defense Technical Information Center.
  47. ^ Wade, Mark (2019). "Little John". Astronautica.
  48. ^ History of the Chaparral/Faar Air Defense System (PDF) (Report). Army Aviation & Missile Command. May 1977. Report No. ADA434389 – via Defense Technical Information Center.
  49. ^ Parsch, Andreas (2002). "General Dynamics MIM-46 Mauler". Directory of U.S. Military Rockets and Missiles.
  50. ^ a b c Barrick, Alan (October 1990). Technology as Deterence: Technology Description Sheets from the AMC 1990 Technology Expo (PDF) (Report). U.S. Army Materiel Command. Report No. ADA228163 – via Defense Technical Information Center.
  51. ^ Cleary, Mark (October 2006). Army Ballistic Missile Programs at Cape Canaveral (PDF) (Report). 45th Space Wing History Office. Archived from the original on 2022-12-01.
  52. ^ Grimwood, James; Strowd, Frances (27 July 1962). History of the Jupiter Missile System (PDF) (Report). heroicrelics.org.
  53. ^ "New HDL Camera Advances Electronic Microminiaturization". Army Research and Development Newsmagazine. Vol. 7, no. 7. July–August 1966. p. 12.
  54. ^ Joyce, James (August 1983). Fluidics: Basic Components and Applications (PDF) (Report). Harry Diamond Laboratories. Report No. HDL-SR-83-9 – via Defense Technical Information Center.
  55. ^ "Fluid Amplifier Pulses Flow of Experimental Heart Pump" (PDF). Army Research and Development Newsmagazine. Vol. 2, no. 11. November 1961. pp. 6–7.
  56. ^ Mary, Donald (September 1979). The High-Spin Tabletop Artillery Simulator (2 in.) (PDF) (Report). Harry Diamond Laboratories. Report No. HDL-TR-1900 – via Defense Technical Information Center.
  57. ^ Restaino, Joe; Curchack, Herbert (1979). "Fuze Power Supplies Tested in Lab". U.S. Army ManTech Journal. 4 (4): 21–23.
  58. ^ Buschman, Jr., A.J. (May 1967). TM-67-7 Component Evaluation During Shock (PDF) (Report). Harry Diamond Laboratories. Report. No. AD0653533 – via Defense Technical Information Center.
  59. ^ Lathrop, Jay (2013). "The Diamond Ordnance Fuze Laboratory's Photolithographic Approach to Microcircuits". IEEE Annals of the History of Computing. 35 (1): 48–55. doi:10.1109/MAHC.2011.83 – via IEEE Xplore.
  60. ^ Jones, Stacy (16 January 1982). "Patents; Slide Rule Calculates Nuclear Blast Effects". The New York Times.
  61. ^ Kelley, C.S.; Scharf, W.D.; Gehman, S.E.; Wasilik, J.H. (December 1978). Nuclear Damage to Point Targets (PDF) (Report). Harry Diamond Laboratories. Report No. HDL-TR-1876 – via Defense Technical Information Center.
  62. ^ "Army Honors 24 Scientists with R&D Achievement Awards" (PDF). Army Research and Development Newsmagazine. Vol. 6, no. 6. June 1965. pp. 1, 3, 42–44. Archived from the original on 2016-12-22.

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