Design of a reusable kinetic energy absorber for an astronaut safety tether to be used during extravehicular activities on the Space Station

The goal of this project is to design a reusable safety device for a waist tether which will absorb the kinetic energy of an astronaut drifting away from the Space Station. The safety device must limit the tension of the tether line in order to prevent damage to the astronaut's space suit or to the structure of the spacecraft. The tether currently used on shuttle missions must be replaced after the safety feature has been developed. A reusable tether for the Space Station would eliminate the need for replacement tethers, conserving space and mass. This report presents background information, scope and limitations, methods of research and development, alternative designs, a final design solution and its evaluation, and recommendations for further work

Protection of Works of Art From Atmospheric Ozone

Assesses the colorfastness of organic colorants and watercolor pigments tested in atmospheric ozone. A summary of a full report of the Environmental Quality Laboratory, California Institute of Technology, Pasadena

FMRI Clustering and False Positive Rates

Recently, Eklund et al. (2016) analyzed clustering methods in standard FMRI packages: AFNI (which we maintain), FSL, and SPM [1]. They claimed: 1) false positive rates (FPRs) in traditional approaches are greatly inflated, questioning the validity of "countless published fMRI studies"; 2) nonparametric methods produce valid, but slightly conservative, FPRs; 3) a common flawed assumption is that the spatial autocorrelation function (ACF) of FMRI noise is Gaussian-shaped; and 4) a 15-year-old bug in AFNI's 3dClustSim significantly contributed to producing "particularly high" FPRs compared to other software. We repeated simulations from [1] (Beijing-Zang data [2], see [3]), and comment on each point briefly.Comment: 3 pages, 1 figure. A Letter accepted in PNA

Rotational torque measurement device

A device for measuring torque applied through a rotating member. A first torsion reference member is fixedly coupled to the rotating member at a first axial position and a second torsion reference member is fixedly coupled to the rotating member at a second axial position. A first detector detects the passage of the first torsion reference member past the first detector upon each full rotation of the rotating member and to generate a first signal upon each passage of the first torsion reference member. A second detector detects the passage of the second torsion reference member past the second detector upon each full rotation of the rotating member and to generate a second signal upon each passage of the second torsion reference member. A controller calculates a phase difference between the first signal and the second signal relative during rotation of the rotating member under a torsional load.https://digitalcommons.mtu.edu/patents/1003/thumbnail.jp

Air Quality Model Evaluation Data for Organics. 2. C_1−C_(14) Carbonyls in Los Angeles Air

As part of a larger experiment that provides a comprehensive set of observations to be used for testing air quality models for organic air pollutant transport and reaction, ambient air samples have been collected using DNPH-coated C_(18) cartridges at four urban locations and one background location in the Los Angeles area and have been analyzed for carbonyls as their DNPH derivatives. Twenty-three carbonyls have been identified and their concentrations measured:  14 aliphatic aldehydes (from formaldehyde to tetradecanal), two aromatics (benzaldehyde and m-tolualdehyde), three ketones (acetone, 2-butanone, and cyclohexanone), one unsaturated carbonyl (crotonaldehyde), and three dicarbonyls (glyoxal, methylglyoxal, and biacetyl). Another 19 carbonyls have been tentatively identified including 11 low molecular weight (MW) and intermediate MW carbonyls (of which four may be due to reactions of ambient NO, NO_2, and ozone with DNPH on the sampling cartridge), four C_4−C_6 dicarbonyls present at trace levels, and four high MW aliphatic carbonyls (C_(15)−C_(18)). Total carbonyl concentrations (4-h samples) averaged 22 ppb at the urban locations and 3.5 ppb at the background location and were highest (29 ppb) at the Azusa, CA, monitoring site that is downwind of downtown Los Angeles. Formaldehyde (urban average 5.3 ppb), acetaldehyde, and acetone accounted for 24%, 18%, and 7%, respectively, of the total carbonyls on a ppbv basis. The nine high MW carbonyls (C_8−C_(14)) accounted for 11−14% of the total carbonyls. The acetaldehyde/formaldehyde concentration ratio averaged 0.75 at the urban locations. Ranking of the measured carbonyls with respect to removal of the hydroxyl radical showed acetaldehyde to be the most important followed by formaldehyde and nonanal. Diurnal and spatial variations in ambient carbonyls levels are briefly examined and appear to be consistent with both direct emissions and in-situ formation during eastward transport over the urban area

Cu(0)-RDRP of methacrylates in DMSO: importance of the initiator

The controlled radical polymerization of methacrylates via Cu(0)-mediated RDRP is challenging in comparison to acrylates with most reports illustrating higher dispersities, lower monomer conversions and poorer end group fidelity relative to the acrylic analogues. Herein, we present the successful synthesis of poly(methyl methacrylate) (PMMA) in DMSO by judicious selection of optimal reaction conditions. The effect of the initiator, ligand and temperature on the rate and control of the polymerization is investigated and discussed. Under carefully optimized conditions enhanced control over the molecular weight distributions is obtained furnishing methacrylic polymers with dispersities as low as 1.10, even at very high conversions. A range of methacrylates were found to be tolerant to the optimized polymerization conditions including hydrophobic, hydrophilic and functional methacrylates including methyl and benzyl methacrylate, ethylene glycol methyl ether methacrylate and glycidyl methacrylate. The control retained during the polymerization is further highlighted by in situ chain extensions yielding well-defined block polymethacrylates

Air Quality Model Evaluation Data for Organics. 2. C_1−C_(14) Carbonyls in Los Angeles Air

As part of a larger experiment that provides a comprehensive set of observations to be used for testing air quality models for organic air pollutant transport and reaction, ambient air samples have been collected using DNPH-coated C_(18) cartridges at four urban locations and one background location in the Los Angeles area and have been analyzed for carbonyls as their DNPH derivatives. Twenty-three carbonyls have been identified and their concentrations measured:  14 aliphatic aldehydes (from formaldehyde to tetradecanal), two aromatics (benzaldehyde and m-tolualdehyde), three ketones (acetone, 2-butanone, and cyclohexanone), one unsaturated carbonyl (crotonaldehyde), and three dicarbonyls (glyoxal, methylglyoxal, and biacetyl). Another 19 carbonyls have been tentatively identified including 11 low molecular weight (MW) and intermediate MW carbonyls (of which four may be due to reactions of ambient NO, NO_2, and ozone with DNPH on the sampling cartridge), four C_4−C_6 dicarbonyls present at trace levels, and four high MW aliphatic carbonyls (C_(15)−C_(18)). Total carbonyl concentrations (4-h samples) averaged 22 ppb at the urban locations and 3.5 ppb at the background location and were highest (29 ppb) at the Azusa, CA, monitoring site that is downwind of downtown Los Angeles. Formaldehyde (urban average 5.3 ppb), acetaldehyde, and acetone accounted for 24%, 18%, and 7%, respectively, of the total carbonyls on a ppbv basis. The nine high MW carbonyls (C_8−C_(14)) accounted for 11−14% of the total carbonyls. The acetaldehyde/formaldehyde concentration ratio averaged 0.75 at the urban locations. Ranking of the measured carbonyls with respect to removal of the hydroxyl radical showed acetaldehyde to be the most important followed by formaldehyde and nonanal. Diurnal and spatial variations in ambient carbonyls levels are briefly examined and appear to be consistent with both direct emissions and in-situ formation during eastward transport over the urban area