47 research outputs found

    Technology for large space systems: A bibliography with indexes (supplement 22)

    Get PDF
    This bibliography lists 1077 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to the researcher or manager engaged in the development of technologies related to large space systems. Subject areas include mission and program definition, design techniques, structural and thermal analysis, structural dynamics and control systems, electronics, advanced materials, assembly concepts, and propulsion

    Development of Shear-Thinning and Self-Healing Hydrogels Through Guest-Host Interactions for Biomedical Applications

    Get PDF
    Hydrogels have emerged as an invaluable class of materials for biomedical applications, owing in part to their utility as structural, bioinstructive, and cell-laden implants that mimic many aspects of native tissues. Despite their many positive attributes, conventional hydrogels face numerous challenges toward translational therapies, including difficulty in delivery (i.e., invasive implantation) as well as limited control over biophysical properties (i.e., porosity, degradation, and strength). To address these challenges, the overall goal of this dissertation was the development of a class of supramolecular hydrogels that can be implanted in vivo by simple injection and that have tunable properties — either innate to the system or achieved through additional modifications. Toward this, we developed guest-host (GH) hydrogels that undergo supramolecular assembly through complexation of hyaluronic acid (HA) separately modified by adamantane (Ad-HA, guest) and β-cyclodextrin (CD-HA, host). Modular modifications were made to GH hydrogels to enable tuning of biophysical properties, including the incorporation of matrix-metalloproteinase cleavable peptides between HA and Ad to form enzymatically degradable assemblies. Additionally, dual-crosslinking (DC) of methacrylated CD-HA (CD-MeHA) and thiolated Ad-HA (Ad-HA-SH) by Michael addition subsequent to GH assembly was explored to stiffen hydrogels in vivo following injection. Finally, injectable and tough double network (DN) hydrogels were fabricated, where GH hydrogels were formed in the presence of an interpenetrating covalent network (methacrylated HA, MeHA) crosslinked by Michael addition with a dithiol under cytocompatible conditions. Both GH and DC hydrogels were further explored in vivo, with application to attenuate the maladaptive left ventricular (LV) remodeling that occurs following myocardial infarction (MI) that can result in heart failure. DC hydrogels reduced stress within the infarct region, prevented early ventricular expansion and thereby ameliorated progressive LV remodeling. Moreover, the preservation of myocardial geometry reduced incidence and severity of ischemic mitral regurgitation — an undesirable and devastating consequence of LV remodeling. Overall, the body of work represents a novel approach to engineer biomaterials with unique properties toward biomedical therapies

    Space Station Systems: a Bibliography with Indexes (Supplement 8)

    Get PDF
    This bibliography lists 950 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included

    Space station systems: A bibliography with indexes (supplement 10)

    Get PDF
    This bibliography lists 1,422 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1989 and December 31, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included

    Microgravity Science and Applications. Program Tasks and Bibliography for FY 1993

    Get PDF
    An annual report published by the Microgravity Science and Applications Division (MSAD) of NASA is presented. It represents a compilation of the Division's currently-funded ground, flight and Advanced Technology Development tasks. An overview and progress report for these tasks, including progress reports by principal investigators selected from the academic, industry and government communities, are provided. The document includes a listing of new bibliographic data provided by the principal investigators to reflect the dissemination of research data during FY 1993 via publications and presentations. The document also includes division research metrics and an index of the funded investigators. The document contains three sections and three appendices: Section 1 includes an introduction and metrics data, Section 2 is a compilation of the task reports in an order representative of its ground, flight or ATD status and the science discipline it represents, and Section 3 is the bibliography. The three appendices, in the order of presentation, are: Appendix A - a microgravity science acronym list, Appendix B - a list of guest investigators associated with a biotechnology task, and Appendix C - an index of the currently funded principal investigators

    Research reports: 1985 NASA/ASEE Summer Faculty Fellowship Program

    Get PDF
    A compilation of 40 technical reports on research conducted by participants in the 1985 NASA/ASEE Summer Faculty Fellowship Program at Marshall Space Flight Center (MSFC) is given. Weibull density functions, reliability analysis, directional solidification, space stations, jet stream, fracture mechanics, composite materials, orbital maneuvering vehicles, stellar winds and gamma ray bursts are among the topics discussed

    Cumulative index to NASA Tech Briefs, 1986-1990, volumes 10-14

    Get PDF
    Tech Briefs are short announcements of new technology derived from the R&D activities of the National Aeronautics and Space Administration. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This cumulative index of Tech Briefs contains abstracts and four indexes (subject, personal author, originating center, and Tech Brief number) and covers the period 1986 to 1990. The abstract section is organized by the following subject categories: electronic components and circuits, electronic systems, physical sciences, materials, computer programs, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

    Technology 2000, volume 1

    Get PDF
    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
    corecore