4,176 research outputs found
Modeling atmospheric effects of the September 1859 Solar Flare
We have modeled atmospheric effects, especially ozone depletion, due to a
solar proton event which probably accompanied the extreme magnetic storm of 1-2
September 1859. We use an inferred proton fluence for this event as estimated
from nitrate levels in Greenland ice cores. We present results showing
production of odd nitrogen compounds and their impact on ozone. We also compute
rainout of nitrate in our model and compare to values from ice core data.Comment: Revised version including improved figures; Accepted for publication
in Geophys. Res. Lett, chosen to be highlighted by AG
Nomenclatural changes for selected Mordellidae (Coleoptera) in North America
New nomenclatural changes are presented for selected North American mordellid beetles (Coleoptera: Mordellidae). The following five genera are newly recorded fi.·om the United States: Mordellaria Ermisch 1950, Falsomordellistena Ermisch 1941, Mordellina Schilsky 1908, Mordellochroa Emery 1876, and
Pseudotolida Ermisch 1950. The following species are transferred from Tomoxia and represent new combinations: Mordellaria borealis (LeConte 1862), Mordellaria fascifera (LeConte 1878), Mordellaria latipalpis (Ray 1946), Mordellaria serval (Say 1835), and Mordellaria undulata (Melsheimer 1845). The following species are transferred fi.·om Mordellistena and represent new combinations: Falsomordellistena hebraica (LeConte 1862) and Falsomordellistena pubescens (Fabricius 1798); Mordellina blatchleyi (Liljeblad 1945), Mordellina pilosella (Ray 1947), Mordellina pustulata (Melsheimer 1845), Mordellina ustulata (LeConte 1862), and Mordellina wichhami (Liljeblad 1945); Mordellochroa scapularis (Say 1824); Pseudotolida
arida (LeConte 1862), Pseudotolida hnausi (Liljeblad 1945), and Pseudotolida lutea (Melsheimer 1845). Mordellina ustulata (LeConte 1862) represents a return to species rank after being treated as a subspecies of Mordellistena andreae LeConte 1862. There are a total of 17 genera of Mordellidae in America north of Mexico
Telemedicine: An expanding new science on land and sea
Several medical and technical men in San Diego County are concerned with the need in many rural communities for a 24-hour day, 7-days a week access to adequate medical care. People isolated from urban areas by travel-times of 40-minutes tend to delay seeking early and effective medical care. The authors were able to assemble quality technology which permits narrow-band video-pictures, better known in the CB trade as ROBOT slow-scan television (SSTV), to be transmitted over telephone lines, by micro-wave, through satellite-bounce, or by HF-radio. These 'ROBOT' pictures can be accompanied with explanatory audio communication and with diagnostic signals from electronic instruments
Potential impact of subsonic and supersonic aircraft exhaust on water vapor in the lower stratosphere assessed via a trajectory model
We employ a trajectory model to assess the impact on the stratosphere of water vapor present in the exhaust of subsonic and a proposed fleet of supersonic aircraft. Air parcels into which water vapor from aircraft exhaust has been injected are run through a 6-year simulation in the trajectory model using meteorological data from the UKMO analyses with emissions dictated by the standard 2015 emissions scenario. For the subsonic aircraft, our results suggest maximum enhancements of ~150 ppbv just above the Northern Hemisphere tropopause and of much less than 50 ppbv in most other regions. Inserting the perturbed water vapor profiles into a radiative transfer model, but not considering the impact of additional cirrus formation resulting from emissions by subsonic aircraft, we find that the impact of subsonic water vapor emissions on the radiative balance is negligible. For the supersonic case, our results show maximum enhancements of ~1.5 ppmv in the tropical stratosphere near 20 km. Much of the remaining stratosphere between 12 and 25 km sees enhancements of greater than 0.1 ppmv, although enhancements above 35 km are generally less than 50 ppbv, in contrast to previous 2-D and 3-D model studies. Radiative calculations based upon these projected water vapor perturbations indicate they may cause a nonnegligible impact on tropical temperature profiles. Since our trajectory model includes no chemistry and our radiative calculations use the most extreme water vapor perturbations, our results should be viewed as upper limits on the potential impacts
Keys and Notes on the Buprestidae (Coleoptera) of Michigan
The distribution and dates of adult activity for Michigan buprestids are discussed. Keys to the genera and species, as well as host information are presented for 116 species and one subspecies. Information on collecting techniques, illustrations of genitalia of 14 species, and scanning electron micrographs of certain structures useful in species identification are presented and discussed. In addition, Pachyschelus confusus, a new species, is described from bush clover
Development of Thermoplastic Composite External Reinforcing of Concrete Decking System
The use of reinforced concrete is very common in the construction of a wide variety of structures. In buildings it is used for floors, beams, columns, and walls. It can also be used in infrastructure as parts of bridges, dams, pavements, etc. Typically, concrete is reinforced with steel, primarily rebar, to carry tensile stresses.
Like every other industry, construction is always looking at ways to advance its technology. The work outlined in this thesis looks to assist in that goal, primarily by looking at options for using a different material than the traditional steel reinforcements to create a reinforced concrete system. Steel-reinforced concrete is susceptible to corrosion from being exposed to the elements and chemicals, like salts. Which reinforced concrete structures frequently experience, and in turn jeopardizes the strength and safety of the structure. Ideal reinforcing materials and methods would give a more durable structure without sacrificing any strength. The material determined to best meet these requirements was a continuous fiber-reinforced thermoplastic (CFRTP), the material selected was a polyethylene terephthalate glycol (PETg) thermoplastic reinforced with E-Glass fibers. The work primarily revolved around ways to enhance the reinforcement of concrete bridge decking. This work could easily be adapted for building floors and slabs. In this thesis, the load requirements adopted were for reinforced concrete bridge decking with a stay-in-place formwork, as provided by the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications.
This thesis outlines the work done towards building a prototype thermoplastic plate that could be used for stay-in-place concrete and contribute towards the tensile reinforcement of the structure. There were three main stages of work that went into this; the first was the creation of a prototype beam that was a hybrid section of concrete, thermoplastic formed as a closed-corrugation section, and rebar. The second stage looked into the secondary processes of bonding already consolidated thermoplastic plates, as well as ways to manipulate the surface. And the final stage was creating a spliced plate of closed-corrugations, resembling a prototype of a stay-in-place formwork for a reinforced concrete bridge deck
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