Download or read book Lubricant Evaluation of the Alpha and Beta Joints Phase 2 written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-08 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research study was conducted to evaluate dry film lubrication of long life space components such as the alpha and beta joints of the Space Station. The problem addressed in the report pertains to the longevity of sputtered MoS2 or ion plated lead films in a rolling contact environment. A special technique was devised for the experiments, which incorporated a coated ball cyclically loaded against a flat plate. At fixed intervals the surface of the coating was photographed at 100X magnification. By computer scanning the photographs, the rate of coating loss was determined. Experimental variables include load and surface finish of the plate. A theory was developed to analyze the state of stress between ball and flat. The stress condition in the ball apparatus was related to the state of stress under rolling contact conditions. Based on the experiments life appeared to decrease with increasing load and increasing surface roughness. An ion plated lead film gave better life than a sputtered MoS2 film. However, by keeping the interfacial shear stress at a low level, adequate coating life was achieved for either coating. For the lead film, the critical stress was about 0.19 GPa (28 ksi). The study dealt only with mechanical wear. Before a coating is selected for a critical space application, other factors such as reaction with atomic oxygen must also be considered. Kannel, J. W. and Stockwell, R. D. Unspecified Center...

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1993 with total page 1790 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1993 with total page 1156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1993 with total page 1832 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1993-02 with total page 1446 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The FY 1992 Scientific and Technical Reports Articles Papers and Presentations written by and published by . This book was released on 1992 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Tech Briefs written by and published by . This book was released on 1993 with total page 1454 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermodynamic Mechanism of Cryogenic Air Minimum Quantity Lubrication Grinding written by Liu, Mingzheng and published by IGI Global. This book was released on 2024-05-02 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: The achievement of high-efficiency and precise grinding of difficult-to-cut metals—like titanium alloys—is essential in the aerospace industry. However, the process often results in thermal damage to the workpiece surface, posing a significant technical challenge. While minimum quantity lubrication (MQL) has been used to aid titanium alloy grinding, its effectiveness is limited by insufficient heat dissipation and lubrication. As an alternative to normal temperature air for carrying micro-lubricants, Cryogenic air has shown promise in improving oil film heat transfer and lubrication performance in the grinding zone, thus reducing workpiece surface thermal damage. The experimental state of the technology demands more comprehensive studies on its effectiveness and on the underlying mechanisms. Thermodynamic Mechanism of Cryogenic Air Minimum Quantity Lubrication Grinding addresses these challenges by providing a theoretical framework for understanding and optimizing cryogenic air minimum quantity lubrication in grinding processes, particularly for titanium alloys. It explores the physical characteristics of lubricants under cryogenic conditions, the influence of low temperatures on atomization effects, droplet formation dynamics, and heat transfer mechanisms within the grinding zone. By establishing quantitative relationships between cryogenic air parameters and lubricant properties, the book lays a foundation for enhancing the cooling lubrication mechanism of cryogenic air MQL in grinding processes. Researchers, scholars, and graduate students in universities and research institutes focusing on machining will find this book invaluable, as it goes beyond the theoretical insights into practical solutions to enhance grinding efficiency and reduce thermal damage.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1968 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Services for Family Planning and Infertility United States 1982 written by Gerry E. Hendershot and published by . This book was released on 1988 with total page 982 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1982 statistics on the use of family planning and infertility services presented in this report are preliminary results from Cycle III of the National Survey of Family Growth (NSFG), conducted by the National Center for Health Statistics. Data were collected through personal interviews with a multistage area probability sample of 7969 women aged 15-44. A detailed series of questions was asked to obtain relatively complete estimates of the extent and type of family planning services received. Statistics on family planning services are limited to women who were able to conceive 3 years before the interview date. Overall, 79% of currently mrried nonsterile women reported using some type of family planning service during the previous 3 years. There were no statistically significant differences between white (79%), black (75%) or Hispanic (77%) wives, or between the 2 income groups. The 1982 survey questions were more comprehensive than those of earlier cycles of the survey. The annual rate of visits for family planning services in 1982 was 1077 visits /1000 women. Teenagers had the highest annual visit rate (1581/1000) of any age group for all sources of family planning services combined. Visit rates declined sharply with age from 1447 at ages 15-24 to 479 at ages 35-44. Similar declines with age also were found in the visit rates for white and black women separately. Nevertheless, the annual visit rate for black women (1334/1000) was significantly higher than that for white women (1033). The highest overall visit rate was for black women 15-19 years of age (1867/1000). Nearly 2/3 of all family planning visits were to private medical sources. Teenagers of all races had higher family planning service visit rates to clinics than to private medical sources, as did black women age 15-24. White women age 20 and older had higher visit rates to private medical services than to clinics. Never married women had higher visit rates to clinics than currently or formerly married women. Data were also collected in 1982 on use of medical services for infertility by women who had difficulty in conceiving or carrying a pregnancy to term. About 1 million ever married women had 1 or more infertility visits in the 12 months before the interview. During the 3 years before interview, about 1.9 million women had infertility visits. For all ever married women, as well as for white and black women separately, infertility services were more likely to be secured from private medical sources than from clinics. The survey design, reliability of the estimates and the terms used are explained in the technical notes.

Download or read book Cumulated Index Medicus written by and published by . This book was released on 2000 with total page 1764 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lubricant Evaluation and Performance II written by Costandy S. Saba and published by . This book was released on 1994 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermal and oxidative stability, deposition and foaming techniques were developed for predicting the performance of candidate 4 cSt lubricants, polyphenyl ether (PPE), C-ether and other experimental fluids for use in advanced aircraft turbine engines. A novel sealed tube test was developed to study the rate of reaction in both liquid and vapor phase using only microliter quantities of the lubricants. Blending agents and/or diluents were used to improve the low temperature properties and high temperature oxidative stability of PPE. In-line magnetic wear sensors were evaluated as condition monitoring devices for oil systems with sensitivity well below 5 micrometers. Microfiltration effect on wear was investigated with the results showing effective reduction in secondary wear. HP-DSC analysis technique was limited as an oxidative stability screening device for PPE but was effective in demonstrating differences among various PPE formulations. The tribological behavior of high temperature fluids was evaluated and compared in the boundary lubrication regime using various steel and ceramic specimens. A sliding three- ball-on-disk wear test device was developed for reducing sample size, controlling scar geometry and determining lubricant consumption rate and tribochemistry. The effect of soft and hard solid particulates on the fatigue and wear lives of rolling elements was investigated using a recently developed three-ball rolling test. High temperature lubricants, Stability, Coking, Foaming, Condition monitoring, Spectrometric oil analysis, Lubricant monitoring, Thermal analysis, Sealed tube oxidation test, Pumpability, Three-Ball-on-disk, Fatigue and wear test.

Download or read book New Trends in Mechanism Science written by Doina Pisla and published by Springer Science & Business Media. This book was released on 2010-08-12 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: After two succesful conferences held in Innsbruck (Prof. Manfred Husty) in 2006 and Cassino in 2008 (Prof Marco Ceccarelli) with the participation of the most important well-known scientists from the European Mechanism Science Community, a further conference was held in Cluj Napoca, Romania, in 2010 (Prof. Doina Pisla) to discuss new developments in the field. This book presents the most recent research advances in Mechanism Science with different applications. Amongst the topics treated are papers on Theoretical kinematics, Computational kinematics, Mechanism design, Mechanical transmissions, Linkages and manipulators, Mechanisms for biomechanics, Micro-mechanisms, Experimental mechanics, Mechanics of robots, Dynamics of multi-body systems, Dynamics of machinery, Control issues of mechanical systems, Novel designs, History of mechanism science etc.

Download or read book World Congress on Medical Physics and Biomedical Engineering 2018 written by Lenka Lhotska and published by Springer. This book was released on 2018-05-29 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book (vol. 2) presents the proceedings of the IUPESM World Congress on Biomedical Engineering and Medical Physics, a triennially organized joint meeting of medical physicists, biomedical engineers and adjoining health care professionals. Besides the purely scientific and technological topics, the 2018 Congress will also focus on other aspects of professional involvement in health care, such as education and training, accreditation and certification, health technology assessment and patient safety. The IUPESM meeting is an important forum for medical physicists and biomedical engineers in medicine and healthcare learn and share knowledge, and discuss the latest research outcomes and technological advancements as well as new ideas in both medical physics and biomedical engineering field.

Download or read book A S M Review of Metal Literature written by American Society for Metals and published by . This book was released on 1967 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Keywords Index to U S Government Technical Reports permuted Title Index written by United States. Department of Commerce. Office of Technical Services and published by . This book was released on 1963 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt: