The degradation of alzak by short wavelength ultraviolet radiation

The changes in reflectance of thermal aluminum coating samples exposed to different irradiating utraviolet wavelengths are discussed. It is shown that the coating is damaged faster and further by 180 to 210 in radiation than by Lyman alpha radiation. On an equivalent incident energy basis, Lyman alpha does less damage than 180 to 210 nm radiation. Above 300 nm no degradation is observed for long exposures and below 300 nm increasing degradation with decreasing wavelength is found. It is concluded that Lyman alpha radiation need not be included in laboratory testing of this thermal coating for spacecraft structures

Solar absorptance and thermal emittance of some common spacecraft thermal-control coatings

Solar absorptance and thermal emittance of spacecraft materials are critical parameters in determining spacecraft temperature control. Because thickness, surface preparation, coatings formulation, manufacturing techniques, etc. affect these parameters, it is usually necessary to measure the absorptance and emittance of materials before they are used. Absorptance and emittance data for many common types of thermal control coatings, are together with some sample spectral data curves of absorptance. In some cases for which ultraviolet and particle radiation data are available, the degraded absorptance and emittance values are also listed

Johnson Space Center's regenerative life support systems test bed

The Regenerative Life Support System (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for the evaluation of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. When completed, the facility will be comprised of two large scale plant growth chambers, each with approximately 10 m(exp 2) growing area. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), will be capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in Lunar or Martian habitats; the other chamber, the Ambient Pressure Growth Chamber (APGC) will operate at ambient atmospheric pressure. The root zone in each chamber will be configurable for hydroponic or solid state media systems. Research will focus on: (1) in situ resource utilization for CELSS systems, in which simulated lunar soils will be used in selected crop growth studies; (2) integration of biological and physicochemical air and water revitalization systems; (3) effect of atmospheric pressure on system performance; and (4) monitoring and control strategies

KRb Feshbach Resonances: Modeling the interatomic potential

We have observed 28 heteronuclear Feshbach resonances in 10 spin combinations of the hyperfine ground states of a 40K 87Rb mixture. The measurements were performed by observing the loss rates from an atomic mixture at magnetic fields between 0 and 700 G. This data was used to significantly refine an interatomic potential derived from molecular spectroscopy, yielding a highly consistent model of the KRb interaction. Thus, the measured resonances can be assigned to the corresponding molecular states. In addition, this potential allows for an accurate calculation of the energy differences between highly excited levels and the rovibrational ground level. This information is of particular relevance for the formation of deeply bound heteronuclear molecules. Finally, the model is used to predict Feshbach resonances in mixtures of 87Rb combined with 39K or 41K.Comment: 4 pages, 3 figure

Radio frequency association of heteronuclear Feshbach molecules

We present a detailed analysis of the production efficiency of weakly bound heteronuclear KRb-Feshbach molecules using radio frequency association in a harmonic trap. The efficiency was measured in a wide range of temperatures, binding energies and radio frequencies. A comprehensive analytical model is presented, explaining the observed asymmetric spectra and achieving good quantitative agreement with the measured production rates. This model provides a deep understanding of the molecule association process and paves the way for future experiments which rely on Feshbach molecules e.g. for the production of deeply bound molecules.Comment: 5 pages, 4 figure

Parametric amplification of vacuum fluctuations in a spinor condensate

Parametric amplification of vacuum fluctuations is crucial in modern quantum optics, enabling the creation of squeezing and entanglement. We demonstrate the parametric amplification of vacuum fluctuations for matter waves using a spinor F=2 Rb-87 condensate. Interatomic interactions lead to correlated pair creation in the m_F= +/- 1 states from an initial unstable m_F=0 condensate, which acts as a vacuum for m_F unequal 0. Although this pair creation from a pure m_F=0 condensate is ideally triggered by vacuum fluctuations, unavoidable spurious initial m_F= +/- 1 atoms induce a classical seed which may become the dominant triggering mechanism. We show that pair creation is insensitive to a classical seed for sufficiently large magnetic fields, demonstrating the dominant role of vacuum fluctuations. The presented system thus provides a direct path towards the generation of non-classical states of matter on the basis of spinor condensates.Comment: 5 pages, 4 figure

The New Avant Garde: Arts Organizations supporting artists with mental illness

Mental illness affects artists and arts organizations in way that is detrimental to the production and presentation of art and the well-being of artists. The research conducted was meant to better understand the background of artists in relation to mental illness and current supportive practices of arts organizations. In this study one-on-one interviews were conducted with directors of various arts organizations. Previous research on the topic of correlation of creativity and mental illness has proven inconclusive and has not yielded novel direction in methods of treatment for artists with mental illness. The best course is to seek supportive policies and actions that arts organizations can effectively provide to artists who are living with mental illness. Artists who have had interventions in mental health issues are able to live productive and creative lives. The interviews conducted for this paper show that while arts organizations are empathetic and aware of artists with mental illness there remains stigma and trepidation when asked to discuss the subject matter. Through existing research and this study, it has been determined that arts organizations have a role to play in developing and understanding best practices when working with artists who suffer from mental illness. Preventative measures are important during the education of young artists along with the implementation of employee benefits that include ensuring proper mental health insurance coverage, stress reduction and Employee Assistance Programs. Arts organizations also bear the responsibility to understand the federal disabilities laws, community resource connections to support agencies, and pursue open dialog with artists.M.S., Arts Administration -- Drexel University, 201

Performance of Sweetpotato for Bioregenerative Life Support

Sweetpotato was successfully grown to harvest maturity in a large-scale atmospherically-closed controlled environment chamber. Yield of edible biomass and capacity for contributing to air revitalization and water recovery were documented. Yield was slightly less than that found in smaller-scale studies, but this is not unusual (Wheeler 1999). Continued work is suggested to improve control of storage root initiation, bulking and vine growth

Developmental differences in affective representation between prefrontal and subcortical structures

Developmental studies have identified differences in prefrontal and subcortical affective structures between children and adults, which correspond with observed cognitive and behavioral maturations from relatively simplistic emotional experiences and expressions to more nuanced, complex ones. However, developmental changes in the neural representation of emotions have not yet been well explored. It stands to reason that adults and children may demonstrate observable differences in the representation of affect within key neurological structures implicated in affective cognition. Forty-five participants (25 children; 20 adults) passively viewed positive, negative, and neutral clips from popular films while undergoing functional magnetic resonance imaging (fMRI). Using representational similarity analysis (RSA) to measure variability in neural pattern similarity, we found developmental differences between children and adults in the amygdala, nucleus accumbens (NAcc), and ventromedial prefrontal cortex (vmPFC), such that children generated less pattern similarity within subcortical structures relative to the vmPFC; a phenomenon not replicated among their older counterparts. Furthermore, children generated valence-specific differences in representational patterns across regions; these valence-specific patterns were not found in adults. These results may suggest that affective representations grow increasingly dissimilar over development as individuals mature from visceral affective responses to more evaluative analyses