50 research outputs found

    Ballast saving balloons with a film of specific optical properties

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    Large plastic balloon play an important role for scientific observations at high altitude in the field of astrophysics and geophysics. In these observations, it has been well recognized that the long duration balloon flights are indispensable for precise observations. For a normal zero pressure balloon, we need to drop ballast to keep a level altitude during day and night to prevent from altitude excursions. This is due to the temperature change of lifting gas, and the duration of the balloon is limited when all the ballast on board the balloon has been exhausted. In this paper, we discuss a possibility of minimizing the temperature variation of the lifting gas using specific balloon films with suitable optical properties and show the optical properties of some test films for this purpose

    A Consideration of Future Flight Material Exposure Experiments in Japan: Advanced Material Exposure Test Working Group\u27s Proposal

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    In Japan, the largest material exposure program “SM/MPAC&SEED (Service Module/ Micro-Particles Capturer and Space Environment Exposure Device) Experiment” has been completed. This program is quite ambitious among the other Japanese materials exposure tests; 3 sets of samples have been exposed for 1, 2 and 3 years in orbit in order to discover the fluence dependence of the material responses. We have learned a lot of lessons from this program. Based on the lessons learned, the “Advanced Material Exposure Test Working Group” has been established by the Committee on Space Utilization in 2007. This working group discussed the current problems of the material exposure program (flight tests) and proposed the future direction of the experimental methodologies. In this presentation, problems and new challenges discussed in this working group will be discussed.ISTS Special Issue: Selected papers from the 27th International Symposium on Space Technology and Scienc

    Gene Expression Changes in the Olfactory Bulb of Mice Induced by Exposure to Diesel Exhaust Are Dependent on Animal Rearing Environment

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    <div><p>There is an emerging concern that particulate air pollution increases the risk of cranial nerve disease onset. Small nanoparticles, mainly derived from diesel exhaust particles reach the olfactory bulb by their nasal depositions. It has been reported that diesel exhaust inhalation causes inflammation of the olfactory bulb and other brain regions. However, these toxicological studies have not evaluated animal rearing environment. We hypothesized that rearing environment can change mice phenotypes and thus might alter toxicological study results. In this study, we exposed mice to diesel exhaust inhalation at 90 µg/m<sup>3</sup>, 8 hours/day, for 28 consecutive days after rearing in a standard cage or environmental enrichment conditions. Microarray analysis found that expression levels of 112 genes were changed by diesel exhaust inhalation. Functional analysis using Gene Ontology revealed that the dysregulated genes were involved in inflammation and immune response. This result was supported by pathway analysis. Quantitative RT-PCR analysis confirmed 10 genes. Interestingly, background gene expression of the olfactory bulb of mice reared in a standard cage environment was changed by diesel exhaust inhalation, whereas there was no significant effect of diesel exhaust exposure on gene expression levels of mice reared with environmental enrichment. The results indicate for the first time that the effect of diesel exhaust exposure on gene expression of the olfactory bulb was influenced by rearing environment. Rearing environment, such as environmental enrichment, may be an important contributive factor to causation in evaluating still undefined toxic environmental substances such as diesel exhaust.</p></div

    Characterization of diesel exhaust.

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    <p>(A) Particle diameter distribution of diesel exhaust particles. (B) Concentrations of gaseous components.</p
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