992 research outputs found

    NASA's plans for future NASTRAN capability

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    Improvements in the NASTRAN systems management office are presented. Among the improvements are the following items: (1) the FEER eigenmethod and its extension to complete eigenvalue problems; (2) the addition of a supersonic flutter package which allows gust response calculations and active control effects as membrane In addition to capabilities mentioned, an error correction information system is also introduced

    Lunar base mission technology issues and orbital demonstration requirements on space station

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    The International Space Station has been the object of considerable design, redesign, and alteration since it was originally proposed in early 1984. In the intervening years the station has slowly evolved to a specific design that was thoroughly reviewed by a large agency-wide Critical Evaluation Task Force (CETF). As space station designs continue to evolve, studies must be conducted to determine the suitability of the current design for some of the primary purposes for which the station will be used. This paper concentrates on the technology requirements and issues, the on-orbit demonstration and verification program, and the space station focused support required prior to the establishment of a permanently manned lunar base as identified in the National Commission on Space report. Technology issues associated with the on-orbit assembly and processing of the lunar vehicle flight elements are also discussed

    Future NSMO plans for maintenance of NASTRAN

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    The objectives of the NASTRAN computer program system are discussed. Specific reference is made to the use of NASTRAN in the space shuttle program. The use of NASTRAN by agencies other than NASA is reported. The subjects presented are: (1) planned developments, (2) capability improvements, (3) efficiency improvements, and (4) new error correction procedure

    Origin of coherent structures in a discrete chaotic medium

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    Using as an example a large lattice of locally interacting Hindmarsh-Rose chaotic neurons, we disclose the origin of ordered structures in a discrete nonequilibrium medium with fast and slow chaotic oscillations. The origin of the ordering mechanism is related to the appearance of a periodic average dynamics in the group of chaotic neurons whose individual slow activity is significantly synchronized by the group mean field. Introducing the concept of a "coarse grain" as a cluster of neuron elements with periodic averaged behavior allows consideration of the dynamics of a medium composed of these clusters. A study of this medium reveals spatially ordered patterns in the periodic and slow dynamics of the coarse grains that are controlled by the average intensity of the fast chaotic pulsation

    Effect of electrolyzed high-pH alkaline water on blood viscosity in healthy adults.

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    BACKGROUND: Previous research has shown fluid replacement beverages ingested after exercise can affect hydration biomarkers. No specific hydration marker is universally accepted as an ideal rehydration parameter following strenuous exercise. Currently, changes in body mass are used as a parameter during post-exercise hydration. Additional parameters are needed to fully appreciate and better understand rehydration following strenuous exercise. This randomized, double-blind, parallel-arm trial assessed the effect of high-pH water on four biomarkers after exercise-induced dehydration. METHODS: One hundred healthy adults (50 M/50 F, 31 ± 6 years of age) were enrolled at a single clinical research center in Camden, NJ and completed this study with no adverse events. All individuals exercised in a warm environment (30 °C, 70% relative humidity) until their weight was reduced by a normally accepted level of 2.0 ± 0.2% due to perspiration, reflecting the effects of exercise in producing mild dehydration. Participants were randomized to rehydrate with an electrolyzed, high-pH (alkaline) water or standard water of equal volume (2% body weight) and assessed for an additional 2-h recovery period following exercise in order to assess any potential variations in measured parameters. The following biomarkers were assessed at baseline and during their recovery period: blood viscosity at high and low shear rates, plasma osmolality, bioimpedance, and body mass, as well as monitoring vital signs. Furthermore, a mixed model analysis was performed for additional validation. RESULTS: After exercise-induced dehydration, consumption of the electrolyzed, high-pH water reduced high-shear viscosity by an average of 6.30% compared to 3.36% with standard purified water (p = 0.03). Other measured biomarkers (plasma osmolality, bioimpedance, and body mass change) revealed no significant difference between the two types of water for rehydration. However, a mixed model analysis validated the effect of high-pH water on high-shear viscosity when compared to standard purified water (p = 0.0213) after controlling for covariates such as age and baseline values. CONCLUSIONS: A significant difference in whole blood viscosity was detected in this study when assessing a high-pH, electrolyte water versus an acceptable standard purified water during the recovery phase following strenuous exercise-induced dehydration

    Space station accommodations for lunar base elements: A study

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    The results of a study conducted at NASA-LaRC to assess the impact on the space station of accommodating a Manned Lunar Base are documented. Included in the study are assembly activities for all infrastructure components, resupply and operations support for lunar base elements, crew activity requirements, the effect of lunar activities on Cape Kennedy operations, and the effect on space station science missions. Technology needs to prepare for such missions are also defined. Results of the study indicate that the space station can support the manned lunar base missions with the addition of a Fuel Depot Facility and a heavy lift launch vehicle to support the large launch requirements

    Linkage and Referral to HIV and Other Medical and Social Services: A Focused Literature Review for Sexually Transmitted Disease Prevention and Control Programs

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    BACKGROUND: Sexually transmitted disease (STD) program and clinic staff play an important role in providing linkage and referrals to programs and services that address the complex medical and psychosocial needs of their clients. We synthesized recent published literature related to effective practices for linkage to care for HIV and referral to other medical and social services. METHODS: Three PubMed searches were conducted to identify relevant studies published since 2004 on (1) linkage to HIV care, (2) referral within STD clinical contexts, and (3) (review articles only) referral practices among all medical specialties. Systematic review procedures were not used. RESULTS: Thirty-three studies were included in this review. Studies highlight the limited value of passive referral practices and the increased effectiveness of active referral and linkage practices. Numerous studies on linkage to HIV care suggest that case management approaches, cultural-linguistic concordance between linkage staff and clients, and structural features such as colocation facilitate timely linkage to care. Integration of other medical and social services such as family planning and alcohol screening services into STD settings may be optimal but resource-intensive. Active referral practices such as having a written referral protocols and agreements, using information technology to help transfer information between providers, and making appointments for clients may offer some benefit. Few studies included information on program costs associated with linkage and referral. CONCLUSIONS: Recent literature provides some guideposts for STD program and clinical staff to use in determining their approach to helping link and refer clients to needed care. Much experience with these issues within STD services remains unpublished, and key gaps in the literature remain
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