Proximal ecological effects of the 1980 eruptions of Mount St. Helens

The diversity of ecosystems and volcanic processes involved in the 1980 eruptions of Mount St. Helens, southwest Washington, provide an excellent setting for examining effects of volcanic events on ecosystems. These eruptions included a lateral blast, debris avalanche, mudflows, pyroclastic flows, and airfall tephra. Affected ecosystems within 30 km of the vent were lakes, streams, upland and riparian forest, and meadows. Ecological disturbances imposed by the Mount St. Helens events were predominantly physical, rather than climatic or chemical which are the dominant classes of disturbances considered in analysis of global catastrophes. Analysis of ecosystem response to disturbance should be based on consideration of composition and structure of the predisturbance system in terms that represent potential survivability of organisms, mechanisms in the primary disturbance, initial survivors, secondary disturbances arising from the primary disturbance and the biological responses to secondary disturbances, invasion of the site by new propagules, interactions among secondary disturbance processes and surviving and invading organisms. Predicting ecosystem response to disturbance is enchanced by considering the mechanisms of disturbance rather than type of disturbance. In the 1980 Mount St. Helens events, the disturbance types, involved primarily the mechanisms of sedimentation, heating, and shear stress. Each disturbance type involved one or more mechanisms. Ecosystem response varied greatly across the landscape. Analysis of ecosystem response to disturbance, regardless of type, should include detailed consideration of the properties of individual species, primary and secondary disturbance mechanisms, and their distributions across landscapes

Effects of quantization on symbol stream combining in a convolutionally coded system

Symbol stream combining has been proposed as a method for arraying signals at different antennas. If the received symbol streams are recorded on tape, it is desirable to limit the required storage without significantly affecting the performance. It is shown that 4-bit quantized symbols introduce an E sub b/N sub o penalty of only 0.05 dB

Heavy-Quark Hybrid Mass Splittings: Hyperfine and "Ultrafine"

It is argued that the heavy-quark limit of QCD requires a certain combination of hyperfine mass splittings in heavy-quark hybrid-meson multiplets to be unusually small. This observation will assist in the exploration of the heavy-quark hybrid spectrum at facilities such as PANDA. Alternatively, a large measured value for this mass splitting indicates that at least one member of the multiplet must contain significant light-quark degrees of freedom.Comment: Version to appear in Few-Body Systems. Substantial modifications from previous version, including extensive additional references and an expanded discussion of relevant operators. 7 page

Factors affecting the retirement of commercial transport jet aircraft

A brief historical background of the technology and economics of aircraft replacement and retirement in the prejet era is presented to see whether useful insights can be obtained applicable to the jet area. Significant differences between the two periods were demonstated. Current technological and operational economic perspectives were investigated in detail. Some conclusions are drawn to aircraft retirement policies

Improved particle charging technique final report

High current ion beam for improving particle charging - hypervelocity accelerato

\u3ci\u3eAnthidium Oblongatum\u3c/i\u3e (Apoidea: Megachilidae) Confirmed as a Michigan Resident, with Notes on Other Michigan \u3ci\u3eAnthidium\u3c/i\u3e Species

The Palearctic wool-carder bee, Anthidium oblongatum (Illiger) is newly documented in Michigan, with vouchers from Kent, Washtenaw, and Wayne Counties. Additional Michigan records are provided for Anthidium manicatum (L.) and the native Anthidium psoraleae Robertson

Dynamics and Decay of Heavy-Light Hadrons

Recent signals for narrow hadrons containing heavy and light flavours are compared with quark model predictions for spectroscopy, strong decays, and radiative transitions. In particular, the production and identification of excited charmed and cs states are examined with emphasis on elucidating the nature of $0^+$ and $1^+$ states. Roughly 200 strong decay amplitudes of $D$ and $D_s$ states up to 3.3 GeV are presented. Applications include determining flavour content in $\eta$ mesons and the mixing angle in $P$ and $D$ wave states and probes of putative molecular states. We advocate searching for radially excited $D_s^*$ states in B decays.Comment: 19 pages, 7 figures, revtex. A numerical error is corrected. Some strong decay rates have change

Desal in So. Cal - Are We There Yet?

Southern California has access to a finite amount of water that is vulnerable to the state’s changing climate and growing population. The increasing population’s water demands and hydrologic variability due to climate change inspire different proposals to solve these water limitations. Seawater or brackish water desalination and wastewater recycling are all water resources that have the potential to help meet the water needs of Southern California, specifically the South Coast Hydrologic Region. Every water resource requires energy to transport, treat, and distribute the water for use; in an era of climate change, when energy use contributes to greenhouse gases, utilities need to consider the most sustainable option for providing water resources at the lowest use of energy. Southern California imports approximately a quarter of its water from the San Francisco Bay Area Delta. This energy intensive process is supported by the hydropower generated throughout the projects conveyance system. Desalinating seawater into potable water, using the method of reverse osmosis, requires large amounts of energy compared to other water resources. Despite this, private companies are still proposing to construct desalination facilities on the coast of California. All new seawater reverse osmosis facility proposals have been rejected except one remaining proposal for a facility in Orange County. Researchers continue to investigate ways to reduce the energy consumption for a seawater reverse osmosis facility but results claim there is little room left for further energy reductions. Other water resources such as wastewater recycling and brackish water reverse osmosis are providing water to the region with lower energy intensity requirements. This study compares the energy intensities between importing water and desalinating ocean water for the South Coast Hydrologic Region. Energy intensities for wastewater and brackish water treatment are also compared against importing water and desalinating sea water. It was found that seawater desalination continues to consume more energy compared to importing water from the State Water Project. It was also found that wastewater recycling and brackish water desalination had the lowest energy intensities compared against importing water and desalinating seawater. It is recommended to find ways for replacing the electricity, sourced by fossil fuels, to supply the Southern California with water resources. It is also recommended to replace a significant portion of water from the State Water Project, that has a considerably large energy intensity for transporting water, with local wastewater recycling and advanced wastewater treatment systems. In the future, all of these water resources have the potential to lower their total energy footprint and convert their electrical supply to a renewable energy source. The analysis on different energy intensities for water resources recommends an establishment of modernized wastewater treatment facilities to support the future water demands of the South Coast Hydrologic Region and ways to lower water resources’ energy intensities