A new laboratory technique has been developed in an effort to simulate the deterioration processes occurring in dental amalgam restorations while they are exposed to attack by the oral environment and simultaneously s...
A new laboratory technique has been developed in an effort to simulate the deterioration processes occurring in dental amalgam restorations while they are exposed to attack by the oral environment and simultaneously subjected to biting forces during mastication. This combined mechanical wear and corrosion action may be one of the major contributors to the degradation of dental amalgam restorations. The technique provides the capability of varying and measuring electrochemical and mechanical parameters during a sliding-wear process in a corrosive environment. A high-copper dental amalgam was selected and tested to demonstrate the applicability of the method in evaluating and studying the effects of the combined action of wear and corrosion processes on dental materials. For the particular amalgam material tested in the present study, it was found that sliding-wear significantly lowered its corrosion potential and increased corrosion rates by at least one order of magnitude.
作者：
JACKSON, HANEEDHAM, WDSIGMAN, DEUSN (RET.)Capt. Harry A. Jackson
USN (Ret.) is a graduate of the University of Michigan in naval architecture and marine engineering and completed the General Electric Company's 3-year advanced engineering course in nuclear engineering. He has been an independent consulting engineer and participated in projects involving deep submergence waste disposal water purification and submarine design both commercial and government. Cdr. William D. Needham
USN is currently assigned as the repair officer of USS Hunley (AS-31) in Norfolk Virginia. He received a regular commission through NROTC at Duke University where he graduated magna cum laude in mechanical engineering. Selected for the Nuclear Power Program he served as a division officer on the USS Grayling (SSN-646) as the production training assistant at the MARE Prototype Reactor in New York and as blue crew engineer of the USS Nathan Hale (SSBN-623) where he completed the requirements to be designated qualified for command of submarines. Following line transfer to the EDO community in 1981 he completed a tour as nuclear repair officer (Code 310) at Norfolk Naval Shipyard and earned master of science in materials science and ocean engineer's degrees at MIT. His awards include the Meritorius Service Medal Navy Commendation Medal Navy Achievement Medal Spear Foundation Award and the Vice Admiral C.R. Bryan Award. Cdr. Needham also holds a master of arts degree in business management from Central Michigan University. Capt. Jackson was technical director of Scorpion Search Phase II. The on-site investigation included descending over 12
000 feet to the bottom of the ocean. He was also supervisor of one of the Navy's largest peacetime shipbuilding and repair programs. His responsibilities included supervision of design production and contract administration. Capt. Jackson was third from the top in managaement of a major shipyard and responsible for design material procurement
work order and financial control of two major surface ship prototypes as well a
Anticipated technological advances in the quieting of potential adversary submarines mandate the use of increasingly effective detection systems for U.S. ASW forces. Based on the assumptions that sonar will continue t...
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Anticipated technological advances in the quieting of potential adversary submarines mandate the use of increasingly effective detection systems for U.S. ASW forces. Based on the assumptions that sonar will continue to be the primary means of detection and that the effectiveness of each individual sonar element will not change markedly, one must increase the projected area of the sonar array to improve its capability. The primary SSN mission of anti-submarine warfare will hence require increasing the hull area devoted to the primary sonar detection system. A revolutionary hull form is proposed that maximizes the area available for this purpose. The advantages and disadvantages of this hull form are discussed and feasibility study level design parameters and arrangements presented.
Investigations are currently being conducted by the Navy and several contractors to determine the technical feasibility and cost effectiveness of advanced regenerative or intercooled-regenerative gas turbines as a nav...
Investigations are currently being conducted by the Navy and several contractors to determine the technical feasibility and cost effectiveness of advanced regenerative or intercooled-regenerative gas turbines as a naval propulsion engine for future mid-size surface combatants. A comparison of the performance characteristics of these engines indicates that significant increases in the thermal efficiency above current simple-cycle engines will result by adding heat exchangers for regeneration alone or with intercooling. Design and performance characteristics of several advanced-cycle gas turbines are described which utilize turbomachinery from various existing simple-cycle gas turbines. Estimates of the weight and volume of recuperators and intercoolers for these conceptual engines are provided. The nominal part-load fuel consumption trends of the simple-cycle and the advanced-cycle engines are used to compare annual fuel usage of typical ships with various combinations of propulsion engines. The relative impacts of the advanced-cycle gas turbine on propulsion machinery spaces are compared with other energy efficient prime movers using the simple-cycle gas turbine as the baseline. Commercial applications for an advanced-cycle gas turbine are surveyed according to output power and market sector. This paper presents an overview of current results and discusses the technology areas which require additional investigation.
United States Naval Applied science Laboratory has been installing and retrieving deep sea mooring installations in southeastern part of Tongue of Ocean (TOTO), Bahamas since 1965;conventional moorings, such as vertic...
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United States Naval Applied science Laboratory has been installing and retrieving deep sea mooring installations in southeastern part of Tongue of Ocean (TOTO), Bahamas since 1965;conventional moorings, such as vertical "taut-wire" rope moorings, as well as moorings of more complex design have been used to expose variety of metallic and nonmetallic materials;because of loss of one mooring, multiple recovery systems was designed;new array, materials under exposure, and operations connected with installation are described.
作者：
AILOR, WILLIAM H.REINHART, FRED M.William H. Ailor has been a member of the Chemical Metallurgy Section of the Metallurgical Research Division
Reynolds Metals Company for nine years. He holds degrees in chemistry and chemical engineering from the University of Tampa Florida and North Carolina State. He is Task Force Chairman of an ASTM 20-Year Test Program for the atmospheric corrosion of metals secretary of ASTM Committee B-3 and is a member of the Electrochemical Society the National Association of Corrosion Engineers and the American Society of Naval Engineers. He formerly taught diesel engineering at North Carolina State. He is a Lieutenant Commander in the Naval Reserve. During World War II he served as engineering officer afloat and later as commanding officer of USS PC 616 and USS Belet (APD-109). Recalled to service in the Korean conflict he served 17 months as executive officer of the USS Robinson (DD 562). He is in the active reserve and formerly was commanding officer of Naval Reserve Surface Division 6–42 in Jacksonville Florida. Currently he is training officer of MSTS Co. 5-1 in Richmond Va. Fred M. Reinhart has been a Senior Project Scientist (Metallurgist) Materials Division
Civil Engineering Department U. S. Naval Civil Engineering Laboratory Port Hueneme California since September 1962. From 1937 to 1962 he was chemist metallurgist supervisory physical metallurgist and supervisory aeronautical materials research engineer Metallurgy Division National Bureau of Standards. Mr. Reinhart has written many papers that have been published in the technical literature and is the author of one technical publication ASTM STP290 “Twenty-Year Atmospheric Corrosion Investigation of Zinc-Coated and Uncoated Wire and Wire Products. He is a member of ASM and was Chairman of the Washington Chapter 1951-52 a member of ASTM with membership on Committees A-5
A-10 and B-3 and was Chairman of Subcommittee XV of A-5 from 1952 to 1962 a member of NACE and was Chairman of the Editorial Review Subcommittee of the Publications Committee f
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