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  • 1
    Electronic Resource
    Electronic Resource
    Preparation of Portland Cement Components by Poly(vinyl alcohol) Solution Polymerization (1999)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 82 (1999), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The four components portland cement-dicalcium silicate, C2S (Ca2SiO4); tricalcium silicate, C3S (Ca3SiO5); tricalcium aluminate, C3A (Ca3Al2O6); and tetracalcium aluminate iron oxide, C4AF (Ca4Al2Fe3O10)-were formed using a solution-polymerization route based on poly(vinyl alcohol) (PVA) as the polymer carrier. The powders were characterized using X-ray diffraction techniques, BET specific surface area measurements, and scanning electron microscopy. This method produced relatively pure, synthetic cement components of submicrometer or nanometer crystallite dimensions, high specific surface areas, as well as extremely high reactivity at relatively low calcining temperatures. The PVA content and its degree of polymerization had a significant influence on the homogeneity of the final powders. Two types of degree of polymerization (DP) PVA were used. Lower crystallization temperatures and smaller particle size powders were obtained from the low-DP-type PVA at optimum content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1999.tb02039.x
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    Paper (German National Licenses)
    Fulltext
  • 2
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    Preparation of Portland Cement Components by Poly(vinyl alcohol) Solution Polymerization (2004)
    Wiley
    Details
    Publication Date: 2004-12-21
    Print ISSN: 0002-7820
    Electronic ISSN: 1551-2916
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Published by Wiley on behalf of American Ceramic Society.
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    PAPER CURRENT
  • 3
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    A Parametric Model of Shoulder Articulation for Virtual Assessment of Space Suit Fit (2016)
    In:  CASI
    Details
    Publication Date: 2019-07-19
    Description: Shoulder injury is one of the most severe risks that have the potential to impair crewmembers' performance and health in long duration space flight. Overall, 64% of crewmembers experience shoulder pain after extra-vehicular training in a space suit, and 14% of symptomatic crewmembers require surgical repair (Williams & Johnson, 2003). Suboptimal suit fit, in particular at the shoulder region, has been identified as one of the predominant risk factors. However, traditional suit fit assessments and laser scans represent only a single person's data, and thus may not be generalized across wide variations of body shapes and poses. The aim of this work is to develop a software tool based on a statistical analysis of a large dataset of crewmember body shapes. This tool can accurately predict the skin deformation and shape variations for any body size and shoulder pose for a target population, from which the geometry can be exported and evaluated against suit models in commercial CAD software. A preliminary software tool was developed by statistically analyzing 150 body shapes matched with body dimension ranges specified in the Human-Systems Integration Requirements of NASA ("baseline model"). Further, the baseline model was incorporated with shoulder joint articulation ("articulation model"), using additional subjects scanned in a variety of shoulder poses across a pre-specified range of motion. Scan data was cleaned and aligned using body landmarks. The skin deformation patterns were dimensionally reduced and the co-variation with shoulder angles was analyzed. A software tool is currently in development and will be presented in the final proceeding. This tool would allow suit engineers to parametrically generate body shapes in strategically targeted anthropometry dimensions and shoulder poses. This would also enable virtual fit assessments, with which the contact volume and clearance between the suit and body surface can be predictively quantified at reduced time and cost.
    Keywords: Computer Programming and Software; Man/System Technology and Life Support
    Type: JSC-CN-36566 , 3D Body Scanning Technologies Conference; Nov 30, 2016 - Dec 01, 2016; Lugano; Switzerland
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 4
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    Functional Mobility Testing: A Novel Method to Create Suit Design Requirements (2008)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: This study was performed to aide in the creation of design requirements for the next generation of space suits that more accurately describe the level of mobility necessary for a suited crewmember through the use of an innovative methodology utilizing functional mobility. A novel method was utilized involving the collection of kinematic data while 20 subjects (10 male, 10 female) performed pertinent functional tasks that will be required of a suited crewmember during various phases of a lunar mission. These tasks were selected based on relevance and criticality from a larger list of tasks that may be carried out by the crew. Kinematic data was processed through Vicon BodyBuilder software to calculate joint angles for the ankle, knee, hip, torso, shoulder, elbow, and wrist. Maximum functional mobility was consistently lower than maximum isolated mobility. This study suggests that conventional methods for establishing design requirements for human-systems interfaces based on maximal isolated joint capabilities may overestimate the required mobility. Additionally, this method provides a valuable means of evaluating systems created from these requirements by comparing the mobility available in a new spacesuit, or the mobility required to use a new piece of hardware, to this newly established database of functional mobility.
    Keywords: Man/System Technology and Life Support
    Type: 08DHM-0067 , Digital Human Modeling Conference 2008; Jun 17, 2008 - Jun 19, 2008; Pittsburgh, PA; United States
    Format: text
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    NASA TECHNICAL REPORTS
  • 5
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    Functional Mobility Testing: A Novel Method to Establish Human System Interface Design Requirements (2008)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Across all fields of human-system interface design it is vital to posses a sound methodology dictating the constraints on the system based on the capabilities of the human user. These limitations may be based on strength, mobility, dexterity, cognitive ability, etc. and combinations thereof. Data collected in an isolated environment to determine, for example, maximal strength or maximal range of motion would indeed be adequate for establishing not-to-exceed type design limitations, however these restraints on the system may be excessive over what is basally needed. Resources may potentially be saved by having a technique to determine the minimum measurements a system must accommodate. This paper specifically deals with the creation of a novel methodology for establishing mobility requirements for a new generation of space suit design concepts. Historically, the Space Shuttle and the International Space Station vehicle and space hardware design requirements documents such as the Man-Systems Integration Standards and International Space Station Flight Crew Integration Standard explicitly stated that the designers should strive to provide the maximum joint range of motion capabilities exhibited by a minimally clothed human subject. In the course of developing the Human-Systems Integration Requirements (HSIR) for the new space exploration initiative (Constellation), an effort was made to redefine the mobility requirements in the interest of safety and cost. Systems designed for manned space exploration can receive compounded gains from simplified designs that are both initially less expensive to produce and lighter, thereby, cheaper to launch.
    Keywords: Man/System Technology and Life Support
    Type: 2008 Summer Bioengineering Conference; Jun 25, 2008 - Jun 29, 2008; Marco Island, FL; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 6
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    A Parametric Model of Shoulder Articulation for Virtual Assessment of Space Suit Fit (2016)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Suboptimal suit fit is a known risk factor for crewmember shoulder injury. Suit fit assessment is however prohibitively time consuming and cannot be generalized across wide variations of body shapes and poses. In this work, we have developed a new design tool based on the statistical analysis of body shape scans. This tool is aimed at predicting the skin deformation and shape variations for any body size and shoulder pose for a target population. This new process, when incorporated with CAD software, will enable virtual suit fit assessments, predictively quantifying the contact volume, and clearance between the suit and body surface at reduced time and cost.
    Keywords: Man/System Technology and Life Support; Cybernetics, Artificial Intelligence and Robotics
    Type: JSC-CN-37701 , International Conference on 3D Body Scanning; Nov 30, 2016 - Dec 01, 2016; Lugano; Switzerland
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 7
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    Use of Traditional and Novel Methods to Evaluate the Influence of an EVA Glove on Hand Performance (2010)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The gloved hand is one of an astronaut s primary means of interacting with the environment, and any restrictions imposed by the glove can strongly affect performance during extravehicular activity (EVA). Glove restrictions have been the subject of study for decades, yet previous studies have generally been unsuccessful in quantifying glove mobility and tactility. Past studies have tended to focus on the dexterity, strength, and functional performance of the gloved hand; this provides only a circumspect analysis of the impact of each type of restriction on the glove s overall capability. The aim of this study was to develop novel capabilities to provide metrics for mobility and tactility that can be used to assess the performance of a glove in a way that could enable designers and engineers to improve their current designs. A series of evaluations were performed to compare unpressurized and pressurized (4.3 psi) gloved conditions with the ungloved condition. A second series of evaluations were performed with the Thermal Micrometeoroid Garment (TMG) removed. This series of tests provided interesting insight into how much of an effect the TMG has on gloved mobility - in some cases, the presence of the TMG restricted glove mobility as much as pressurization did. Previous hypotheses had assumed that the TMG would have a much lower impact on mobility, but these results suggest that an improvement in the design of the TMG could have a significant impact on glove performance. Tactility testing illustrated the effect of glove pressurization, provided insight into the design of hardware that interfaces with the glove, and highlighted areas of concern. The metrics developed in this study served to benchmark the Phase VI EVA glove and to develop requirements for the next-generation glove for the Constellation program.
    Keywords: Space Sciences (General)
    Type: JSC-CN-20142 , 40th International Conference on Environmental Systems; Jul 11, 2010 - Jul 15, 2010; Barcelona; Spain
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 8
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    Evidence Report: Risk of Injury and Compromised Performance due to EVA Operations (2017)
    In:  CASI
    Details
    Publication Date: 2019-07-12
    Description: Given the high physiological and functional demands of operating in a self-contained EVA or training suit in various gravity fields and system environments, there is a possibility that crew injury can occur and physiological and functional performance may be comprised.
    Keywords: Aerospace Medicine
    Type: JSC-CN-39092
    Format: application/pdf
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    NASA TECHNICAL REPORTS
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