The JPL MSAT mobile laboratory and the pilot field experiments

A Mobile Laboratory/Propagation Measurement Van (PMV) was developed to support the field experiments of the Mobile Satellite Experiment (MSAT-X) Project. This van was designed to provide flexibility, self-sufficiency and data acquisition to allow for both measurement of equipment performance and the mobile environment. The design philosophy and implementation of the PMV are described. The Pilot Field Experiments and an overall description of the three experiments in which the PMV was used are described

Field trials of a NASA-developed mobile satellite terminal

Various field trials have been performed to validate and optimize the technologies developed by the Mobile Satellite Experiment (MSAT-X). For each of the field experiments performed, a brief description of the experiment is provided, followed by a summary of the experimental results. Emphasis is placed on the two full scale land mobile and aeronautical mobile experiments. Experiments planned for the near future are also presented

Sediment-water exchange in shallow water estuarine sediments

Pore water profiles in shallow estuarine sediments of Puget Sound show the characteristics of enhanced interstitial-water transport by animal activity. Using an in situ 3H experiment and dissolved silicate profiles we evaluate the transport parameter due to animal activity in the surface 20 cm of sediments to be 1–5 × 10–7 s–1 which is in the range of similar parameters determined in other nearshore environments in the U.S. The fluxes of alkalinity, ammonia and silicate across the sediment-water interface due to biological processes are greater than that by one-dimensional molecular diffusion. For the metals Fe, Mn, Cu, Ni and Cd the dominant transport mechanism depends upon the depth at which the metal is released to the pore waters. Probably the most important effect of biological activity on metal remobilization is the removal of sulfide from the pore waters, via ventilation of sediments with oxic overlying water, allowing the enrichment of dissolved metals which might otherwise be very low in concentration due to insoluble sulfide formation. The result is a greatly enhanced flux of metals to the bottom waters

Early Years Parenting Mediates Early Adversity Effects on Problem Behaviors in Intellectual Disability

A family developmental framework was applied to data from families of children with intellectual disabilities to understand the role of parenting in the path from early adversity to problem behaviors in mid-childhood. Data from 9 months to 11 years tested the Family Stress Model in families of 555 children. Adversarial parenting between 3 and 5 years mediated the path from early adversity (family poverty and maternal psychological distress at nine months) to problem behaviors at 7 and 11 years. Positive parent-child relationship only mediated the path to conduct problems. Multiple mediation was not present. Early adversity impacts both positive parent-child relationship and adversarial parenting between three and five, but the latter is crucial for problem behaviors in mid-childhood

14-11 Travel in Adverse Winter Weather Conditions by Blind Pedestrians

Winter weather creates many orientation and mobility (O&M) challenges for people who are visually impaired. Getting the cane tip stuck is one of the noticeable challenges when traveling in snow, particularly when the walking surface is covered in deep snow. We compared four different cane tips: 1) metal glide, 2) marshmallow roller, 3) roller ball, and 4) bundu bahser. There was a statistically significant difference in frequency of sticking among the different cane tips. Post hoc analyses revealed that the sticking frequency for the metal glide tip was significantly higher than that for the roller ball tip, for the bundu basher tip, and for the marshmallow roller tip. In addition, there was a statistically significant difference in sticking frequency between the marshmallow roller tip and the roller ball tip. Cane tip shape appears to have contributed to differences in sticking frequency. For example, the metal glide tip, being the smallest and more sharply angled among the four cane tips, tended to get stuck on snow more often than more rounded and larger cane tips. Differences in sticking frequency among the cane tips observed in this study appear to be large enough to be practically significant for cane users and practitioners