NASA Thesaurus. Volume 1: Hierarchical listing

There are 16,713 postable terms and 3,716 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary

NASA Thesaurus. Volume 1: Alphabetical listing

The NASA Thesaurus -- Volume 1, Alphabetical Listing -- contains all subject terms (postable and nonpostable) approved for use in the NASA scientific and technical information system. Included are the subject terms of the Preliminary Edition of the NASA Thesaurus (NASA SP-7030, December 1967); of the NASA Thesaurus Alphabetical Update (NASA SP-7040, September 1971); and terms approved, added or changed through May 31, 1975. Thesaurus structuring, including scope notes, a generic structure with broader-term/narrower-term (BT-NT) relationships displayed in embedded hierarchies, and other cross references, is provided for each term, as appropriate

NASA Tech Briefs, December 1992

Topics include: Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

Defense Technical Information Center thesaurus

This DTIC Thesaurus provides a basic multidisciplinary subject term vocabulary used by DTIC to index and retrieve scientific and technical information from its various data bases and to aid DTIC`s users in their information storage and retrieval operations. It includes an alphabetical posting term display, a hierarchy display, and a Keywork Out of Context (KWOC) display

Method for Characterising and Quantifying Volumetric Edge-Wear in Ceramic-On-Ceramic Hip Arthroplasty Devices

The number of primary total hip arthroplasty (THA) surgeries has been increasing worldwide over the last decades reaching over 200 per 100,000 population with a high degree of variability between countries[1-3]. National Joint registry 2017 report mentions that in the UK during the last decade, 711,765 primary surgeries have been carried out in comparison to 80,042 revision surgeries to replace joints that have failed either prematurely or at the end of their useful life[1]. The life expectancy of a hip prosthesis is commonly expected to be 15-20 years. Of all current commonly used bearing surface combinations,the use of fourth generation ceramic-on-ceramic bearings have proved to be very efficient[4]and has grown in popularity for primary hip surgery in the decadepreceding 2017[1]. This is due to the low reported wear volumes associated with all ceramic bearings [5]as well as the fact that ceramic debris being bio-inert overcomes the commonly reported issues of systemic cobalt chromium ion concentration as reported in metal-on-metal bearings [6, 7]and issues of osteolysis induced by polyethylene wear debris in metal-on-UHMWPE [8, 9]. The interest in ceramic-on-ceramic is elevated also due to significant improvements in material properties and manufacturing process [10]. However, the ceramic-on-ceramic hip prosthesis are reported to squeak in-vivo [11, 12]which appears to be linked to edge-loading [13]. Also, it has been reported that an unusual stripe pattern of wear can occur in some retrieved acetabular cup liners [14]and it has further been postulated that this is caused by cup liner edge loading [15]. The combined measurement challenge of wear occurring at the edge of the acetabular liner of a low-wearing ceramic-on-ceramic prosthesis is therefore considerable. Various wear measurement methods have been developed to measure wear in hip prostheses[12, 16-18], yet current recognised industrial practice regarding in vitro measurement of wear for hip joint prostheses involves either gravimetric assessment or co-ordinate measurement [19].Due to the considerable challenge in geometrical characterization of edge wear, current literature regarding the assessment of edge-wear in acetabular cup liners has been confined to in-vitro simulator studies and gravimetric measurement to assess wear volumes. Geometric characterisation of wear is essential in determining the contact conditions during gait and subsequent calculation of point and magnitude of the maximum stress condition. It is, therefore, vital that a robust and reliable method for geometric measurement and analysis of edge wear is created. Current methodologies for assessing wear on acetabular cups have focused on quantifying the amount of material loss on the bearing surface. The bearing surface is constituted by well-defined geometry and surface characteristics. As such methods are able to estimatethe unworn surface and determine the amount of material loss. However, the main limitation of these methods was that wear could only be estimated on the well-defined spherical geometry of bearing surface. Hence, when edge wear is present at the boundary between the bearing surface and outer cup geometry it is normally thresholded during analysis process when using current methods. This can potentially underestimate the amount of wear present on acetabular cups. This study provides details of the requirements and methodologies for the measurement and analysis of edge wear in ceramic-on-ceramic liners. Two methodologies have been developed based on measurements using a coordinate measuring machine and a roundness measuring machine. Both methods havebeen evaluated using ceramic liners tested in vitro under edge loading conditions, and the volume loss is compared to gravimetric measurements. The results show that both methods have the required resolution to measure volume loss of less that 1mm3and are thus capable of providing a volume loss estimation for ceramic-on-ceramic acetabular liners

NASA SBIR abstracts of 1991 phase 1 projects

The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included

Aeropropulsion 1987

Papers from the Aeropropulsion '87 Conference, held at the NASA Lewis Research Center (LeRC), are presented. Unclassified presentations by LeRC and NASA Headquarters senior management and many LeRC technical authors covered the philosophy and major directions of the LeRC aeropropulsion program, and presented a broad spectrum of recent research results in materials, structures, internal fluid mechanics, instrumentation and controls, and both subsonic and high-speed propulsion technology

Technology 2000, volume 1

The purpose of the conference was to increase awareness of existing NASA developed technologies that are available for immediate use in the development of new products and processes, and to lay the groundwork for the effective utilization of emerging technologies. There were sessions on the following: Computer technology and software engineering; Human factors engineering and life sciences; Information and data management; Material sciences; Manufacturing and fabrication technology; Power, energy, and control systems; Robotics; Sensors and measurement technology; Artificial intelligence; Environmental technology; Optics and communications; and Superconductivity

Metalcasting Competitiveness Research. Final Report

This report comprises eleven separate reports: prediction of non- metallic particle distribution, electromagnetic separation of inclusions from molten Al alloy, clean steel castings, waste stream identification and treatment, elastic wave lithotripsy for removal of ceramic from investment castings, metal penetration in sand molds, mold-metal interface gas composition, improved Alloy 718, specifications for iron oxide additions to no-bake sands, criteria functions for defect prediction, and computer-aided cooling curve analysis