From these calculations it is shown that if a deformation induced vacancy flux should occur as hypothesized, it will result in a Zn concentration differrence between the center of a dislocation cell and the dislocatio...
From these calculations it is shown that if a deformation induced vacancy flux should occur as hypothesized, it will result in a Zn concentration differrence between the center of a dislocation cell and the dislocation cell walls of at least 10 −3 atom fraction, or possibly more in cylically deformed CuZn alloy. The zinc concentration should decrease near the vacancy sinks and increase near the sources. Hence, if such concentration gradients can be shown to develop during steady state fatigue, they will provide evidence as to the dominant direction of vacancy flow during fatigue. Such measurements will also provide insight into the magnitude of the vacancy generation rate and should lend support to one of the theories mentioned in the introduction. Such measurements require concentration determinations at the sensitivity of 10 −4 over a spatial dimension approximately 1/10 of the cell size, or approximately 0.2 μm. A step counting energy dispersive x-ray technique such as available on modern electron microprobes with measurement of Cu and Zn peaks or the use of STEM with energy dispersive x-ray capability should provide the answers. We are in the process of developing collaborative efforts to carry out these experiments. These calculations also estimate the vacancy flux at the cell wall due to the creation of 1 ppm vacancies per second [7] during cyclic deformation as sufficient to generate one unit climb of every dislocation in the cell wall during 35 cycles under typical low cycle fatigue deformation conditions. The rapid dislocation rearrangement and recovery in the cell walls produced by this flux of vacancies lends additional credibility to the cell shuttling model.
In this study molecular alignment in copolymers of polyethylene terephthalate (PET) and p-hydroxybenzoic acid (PHB) was examined by means of differential radial distribution function (DRDF) analysis of wide angle X-ra...
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In this study molecular alignment in copolymers of polyethylene terephthalate (PET) and p-hydroxybenzoic acid (PHB) was examined by means of differential radial distribution function (DRDF) analysis of wide angle X-ray scattering data. The study was carried out using two representative copolymers with the PHB content of 30 and 60 mol%. The DRDF curves for the amorphous and the partially crystalline samples of these copolymers showed periodic intermolecular peaks up to various radial distances. The appearance of these peaks at periodicity suggested the existence of more-or-less parallel chain segments in the copolymers. The extent of the lateral molecular organization was for the amorphous copolymers containing 30 and 60 mol% PHB, respectively. A substantial structural difference was therefore shown for the copolymers in this composition range. The DRDF curve for the amorphous copolymer with 30 mol% PHB was found to be very similar to that for the previously reported glassy PET with 0 mol% PHB, indicating that the two materials had almost the same intermolecular structure. The structural information revealed by these DRDF results was in agreement with the various property changes caused by varying PHB contents of the copolymers.
作者：
SONENSHEIN, RADM. NATHANUSNThe author graduated from the U.S. Naval Academy in the Class of 1938. His work has included instruction in Naval Construction and Marine Engineering at the Massachusetts Institute of Technology leading to a Master of Science degree in 1944 and the Advanced Management Program at Harvard Graduate School of Business in 1964. As an Engineering Duty Officer (EDO)
he has served in various Navy commands including the Mare Island Naval Shipyard the former New York Naval Shipyard the USS Philippine Sea (CVA-47) during the Korean War as Chief Engineer and CINCPACFLT and COMSERVPAC Staffs as Fleet and Force Maintenance Officer. Within the Naval Ship Systems Command and its predecessor BUSHIPS his duties have included Director of the Facilities Division Head of the Hull Design Branch Director of the Ship Design Division Assistant Chief for Design Shipbuilding and Fleet Maintenance and as Commander Naval Ship Systems Command from 1969 until 1972. Other duties have included an assignment as the Project Manager for the Navy's Fast Deployment Logistic Ship Project from 1965 to 1967 Deputy Chief of Naval Material for Logistic Support from 1967 to 1969 and Chairman of the Naval Material Command Shipbuilding Council which commenced upon completion of his tour as Commander NAVSHIPS in 1972. On 4 September 1973 he was appointed Director of the Defense Energy Task Group (DETG) and subsequently on 15 November 1973 as Director of Energy for the Department of Defense. A former President of ASNE from 1970 to 1971 he is currently Vice-President of the American Society of Naval Architects and Marine Engineers. In addition he is a member of the honorary engineering society Sigma Xi and listed among those in Who's Who in America.
作者：
WILSON, TBUSN (RET)COMMANDER T. B. WILSON
JR. USN (RET) served as an enlisted man aboard USS SPROSTON (DD 577) and other Destroyer Forces Atlantic Fleet ships prior to his entrance into the U.S. Naval Academy in 1944. After graduating in 1948 he served on PHIBPAC ships until 1951 when he entered Webb Institute of Naval Architecture. He graduated from Webb with a Bachelor of Science Degree in Marine Engineering and a Master of Science Degree in Naval Architecture in 1953. He has served as Planning and Design Officer for the Supervisor of Shipbuilding in Jacksonville Florida was Assistant Material Officer on the Staff
Commander Mine Forces U.S. Pacific Fleet and as Docking Officer and Ship Superintendent Long Beach Naval Shipyard. He then served in the Engineering Department of the USS RANDOLPH (CVS 15) after which he reported to the Bureau of Ships where he worked as Aircraft Carrier Project Officer in the Contract Design Division. He was Industrial Officer at the David Taylor Model Basin prior to assuming duties as Fleet Maintenance Officer Staff Commander in Chief U.S. Naval Forces Europe. Prior to retiring on 1 January 1969 he served as Repair Officer U.S. Naval Support Activity Saigon. Since retirement he has been Manager of System Engineering and Senior Member of the Technical Staff for the LHA Program at Litton's Advanced Marine Technology Group and is currently Manager Engineering Design with HARCO Engineering the design division of Harbor Boat Building Company Terminal Island California.
作者：
WILSON, THOMAS B.U.S. NAVYTHE AUTHOR: has served in the U.S. Navy since 1942
starting with service in the Destroyer Forces Atlantic Fleet as a machinist mate on destroyer and destroyer tender types until entry into the U.S. Naval Academy in June 1944. He graduated in 1948 and served in the Amphibious Force US. Pacific Fleet on attack troop transports as Gunnery Officer Deck Division Officer Salvage Officer and Boat Group Officer until 1951 when he entered the Navy's Postgraduate Training Program. He received a Master of Science Degree in Naval Architecture from Webb Institute of Naval Architecture in 1953. Concurrently he entered the ranks of “Engineering Duty Only” Officers assigned to the Bureau of Ships Department of the Navy. He has served on the waterfront in Naval Shipyards in supervisory positions on new construction conversion repair and docking of ships ranging from minesweepers to attack aircraft carriers. Other assignments include Planning and Design Officer in a Supervisor of Shipbuilding Office Assistant Material Officer for Mine Forces Pacific Fleet Damage Control and Engineer Officer on the USS. RANDOLPH (CVS 15) as Project Coordinator of Aircraft Carrier design in the Ship Design Division of the Bureau of Ships and as Industrial Officer of the David Taylor Model Basin at Carderock Maryland. He is currently serving as the Fleet Maintenance and Support Officer on the Staff of the Commander in Chief U.S. Naval Forces Europe. The opinions expressed in this article are his own and in no way reflect those of the Naval Ship Systems Command or the Department of Navy.
We report first-principles calculations for Fe4Al11-x where 0 ≤ x ≤ 3 and for Fe4Al11-yZny for 0≤ y ≤ 1. We investigate the correlation of the magnetic and vibrational behavior with the density of states at the Fe...
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作者：
D'EMIDIOUSNThe author Prior to entering the Navy
Commander D'Emidio received a Bachelor of Science degree in Civil Engineering from the Newark College of Engineering (1951) and a Master of Science degree in Sanitation Engineering from the University of Michigan (1960). He was employed as a Sanitary Engineer Designer for the Architect/Engineer firm of Porter Urquhart-Skidmore Owings and Merrill in North Africa. After completing Officer Candidate School in 1953 Commander D'Emidio served in the Public Works Department of the Naval Air Material Center Philadelphia Pennsylvania. In 1957 he became Officer in Charge of Construction for three U.S. Air Force Strategic Air Command Bases in Spain. After successful tours of duty as Public Works Officer Naval Air Station Columbus Ohio and Technical Department Officer Construction Battalion Center Davisville Rhode Island he was assigned to the Naval Nuclear Power Division of Naval Facilities Engineering Command. In this capacity he assisted in the procurement and shipment of the Navy's first nuclear power plant which was installed by Seabees at McMurdo Sound Antartica in 1962. Later that year he became Civil Engineer Corps Advisor to the Brazilian Navy where he assisted in the design of a carrier-sized dry dock. In 1965 he returned to the Naval Facilities Engineering Command to establish the Navy's first Comprehensive Air and Water Pollution Abatement Program. During this tour of duty he successfully defended the Navy's Pollution Abatement Program through the Congress. Commander D'Emidio is a licensed Professional Engineer in the states of New Jersey and Ohio and is a Diplomat in the American Academy of Environmental Engineers. He is also a member of the American Society of Civil Engineers the Society of Military Engineers and the American Public Works Association. Commander D'Emidio is assigned to the Office of the Chief of Naval Operations where he is the Director of the Navy Environmental Protection Division.
作者：
WILSON, THOMAS B.U.S. NAVYCOMMANDER THOMAS B. WILSON
JR. U.S. NAVY has served in the U.S. Navy since 1942 starting as an enlisted man in the Destroyer Forces Atlantic Fleet prior to entry into the U.S. Naval Academy in 1944. He graduated in 1948 and served in the Amphibious Forces U.S. Pacific Fleet on attack troop transports until 1951 when he entered the Navy's Postgraduate Training Program. Concurrently in 1953. he received a Master of Science Degree in Naval Architecture from Webb Institute of Naval Architecture and entered the ranks of the “Engineering Duty Officers” assigned to the Naval Ship Systems Command (formerly the Bureau of Ships) Department of the Navy. He has served on the waterfront in Naval Shipyards in supervisory positions on new construction conversion repair and dry-docking of ships ranging from minesweepers to attack aircraft carriers. Other duty includes tours in Supervisor of Shipbuilding Jacksonville Florida the Material Section of Mine Forces Pacific Fleet the Engineering Department of the U.S.S. RANDOLPH (CVS 15) Project Coordinator for Aircraft Carrier Design in the Bureau of Ships and Industrial Officer of the David Taylor Model Basin. He is currently the Fleet Maintenance Officer on the Staff Commander in Chief U.S. Naval Forces Europe.
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