Potential bronchoconstrictor stimuli in acid fog.

Acid fog is complex and contains multiple stimuli that may be capable of inducing bronchoconstriction. These stimuli include sulfuric and niric acids, the principal inorganic acids present; sulfites, formed in the atmosphere as a reaction product of sulfur dioxide and water droplets; fog water itself, a hypoosmolar aerosol; the organic acid hydroxymethanesulfonate, the bisulfite adduct of formaldehyde; and gaseous pollutants, e.g., sulfur dioxide, oxides of nitrogen, ozone. Given this complexity, evaluation of the respiratory health effects of naturally occurring acid fog requires assessment of the bronchoconstrictor potency of each component stimulus and possible interactions among these stimuli. We summarize the results of three studies that involve characterization of the bronchoconstrictor potency of acid fog stimuli and/or their interaction in subjects with asthma. The results of the first study indicate that titratable acidity appears to be a more important stimulus to bronchoconstriction than is pH. The results of the second study demonstrate that sulfite species are capable of inducing bronchoconstriction, especially when inhaled at acid pH. The results of the third study suggest that acidity can potentiate hypoosmolar fog-induced bronchoconstriction

Simulating F-22 Heavy Maintenance and Modifications Workforce Multi-Skilling

The Air Force faces significant fiscal challenges in the coming years. The aircraft maintenance depot activities at Ogden ALC, Oklahoma City ALC and Warner-Robins ALC face complex operating environments due to the diversity of aircraft or mission design series (MDS) maintained by each depot and the variability of maintenance requirements for each MDS. Further complicating their operations is the variability of maintenance actions required from one aircraft to another within each MDS and a highly specialized workforce that has inherent inflexibility to compensate for the workload variability. Air Force Materiel Command is reviewing maintenance personnel multi-skilling as a method to efficiently absorb the variability of workload and maintenance requirements between aircraft. This research conducts an objective analysis of the F-22 Heavy Maintenance Modification Program by building a discrete event simulation in ARENA 14? and performing a series of designed experiments. The study analyzes whether using a multi-skilled (flexible) workforce will have an impact on productivity of depot maintenance personnel through simulation of several multi-skilling policies. The research shows that multi-skilling policies can significantly outperform overtime-based production timelines at less cost, even if individual skill proficiencies decline

Acer palatum (Japanese Maple) ID#52

Location: Miley Residence Hall Height: 9.01600m Diameter at Breast Height: 135.7cm Condition: Good Age Class: Maturehttps://digitalcommons.salve.edu/bio140_arboretum/1000/thumbnail.jp

S-band omnidirectional antenna for the SERT-C satellite

The program to design an S-band omnidirectional antenna system for the SERT-C spacecraft is discussed. The program involved the tasks of antenna analyses by computer techniques, scale model radiation pattern measurements of a number of antenna systems, full-scale RF measurements, and the recommended design, including detailed drawings. A number of antenna elements were considered: the cavity-backed spiral, quadrifilar helix, and crossed-dipoles were chosen for in-depth studies. The final design consisted of a two-element array of cavity-backed spirals mounted on opposite sides of spacecraft and fed in-phase through a hybrid junction. This antenna system meets the coverage requirement of having a gain of at least minus 10 dBi over 50 percent of a 4 pi steradian sphere with the solar panels in operation. This coverage level is increased if the ground station has the capability to change polarization

Three-level filter for increased depth of focus and Bessel beam generation

Author Posting. © Optical Society of America, 2012. This article is posted here by permission of Optical Society of America for personal use, not for redistribution. The definitive version was published in Optics Express 20 (2012): 27212-27221, doi:10.1364/OE.20.25.027212.A novel axially-symmetric filter for increasing focal depth and generating an approximation to a Bessel beam is proposed. It consists of an array of rings of strength –1,0 and 1. The design is based on an analytic solution, and combines high resolution in the transverse direction with good efficiency. One presented design increases the depth of focus compared with a standard lens by more than 30 times, with a very flat axial intensity distribution over this range. Effects of discretization are discussed. Various different approaches to increasing depth of focus are compared, to put the new design into perspective.Support from the Singapore-MIT Alliance for Research and Technology (SMART) Program is acknowledged. SM acknowledges a post-doctoral fellowship from Human Frontier Science Program (HFSP)