4,148 research outputs found
Steady States of a Nonequilibrium Lattice Gas
We present a Monte Carlo study of a lattice gas driven out of equilibrium by
a local hopping bias. Sites can be empty or occupied by one of two types of
particles, which are distinguished by their response to the hopping bias. All
particles interact via excluded volume and a nearest-neighbor attractive force.
The main result is a phase diagram with three phases: a homogeneous phase, and
two distinct ordered phases. Continuous boundaries separate the homogeneous
phase from the ordered phases, and a first-order line separates the two ordered
phases. The three lines merge in a nonequilibrium bicritical point.Comment: 14 pages, 24 figure
Annual Report to Portland City Council on Municipal Activities for 1951
https://digitalmaine.com/portland_municipal_reports/1000/thumbnail.jp
A revision of the genus Listronotus (Curculionidae, Coleoptera)
Dissertation (Ph.D.)--University of Kansas, Entomology, 1938
Potential use of offshore marine structures in rebuilding an overfished rockfish species, bocaccio (Sebastes paucispinis)
Although bocaccio (Sebastes paucispinis) was an economically important rockfish species along the west coast of North America, overfishing has reduced the stock to about 7.4% of its former unfished population. In 2003, using a manned research submersible, we conducted fish surveys around eight oil and gas platforms off southern California as part of an assessment of the potential value of these structures as fish habitat. From these surveys, we estimated that there was a minimum of 430,000 juvenile bocaccio at these eight structures. We determined this number to be about 20% of the average number of juvenile bocaccio that survive annually for the geographic range of the species. When these juveniles become adults, they will contribute about one percent (0.8%) of the additional amount of fish needed to rebuild the Pacific Coast population. By comparison, juvenile bocaccio recruitment to nearshore natural nursery grounds, as determined through regional scuba surveys, was low in the same year. This research demonstrates that a relatively small amount of artificial nursery habitat may be quite valuable in rebuilding an overfished species
One-dimensional Drainage of Soil ProfIle with Root Extraction
A one-dimensiunal n1l1nrncalmodel was developed to solve an unsaturated flaw equation for a soil prafik that represents a soil-plant-water system with a shallow water table above an impermeable layer. The diffusivity form of the Richard's equation was solved using Crank Nicalson implicit finite difference scheme and a general Newton-Raphson interative method. The model was used to simulate volume tric moisture content, capillary pressure, and position of water tab. It was also used to simulate the cumulative soil water depltion" within" the soil profile. Result from the compare model compared re compared reasonably we" measured lysimeter data
Basin water management
Presented at Contemporary challenges for irrigation and drainage: proceedings from the USCID 14th technical conference on irrigation, drainage and flood control held on June 3-6, 1998 in Phoenix, Arizona.Includes bibliographical references.The required level of management of the fresh water supply practiced within a given watershed is defined by all of the physical, chemical, economic, environmental, and sociological factors involved. Efficiency of water use, consumptive versus non-consumptive utilization of water, diversion requirements, and environmental requirements all need to be understood and balanced to optimize use of the available water. Where watersheds span states and sovereign nations, treaties and agreements are required for orderly use of the fresh water resource. Understanding of the nature of water use and the hydrology of the water resource system is a key element in rational utilization of the resource. Elevation, water quality, and temporal availability are some of the parameters that must be considered. Ground water and surface water need to be treated as a single resource for effective management
Abandoned Railroads in Maine: Their Potential for Trail Use
Abandoned railroads in Maine : their potential for trail use / prepared by Arnold S. Biondi, Frederick W. Lyman for the Maine Department of Parks & Recreation, Planning & Research Division
This report, conceived as part of an in-depth analysis of existing and potential trail facilities in Maine, attempts to provide some concrete information and recommendations as the first step in the realization of a Statewide railroad right-of- way trail system.https://digitalcommons.usm.maine.edu/me_collection/1014/thumbnail.jp
Release of mercury halides from KCl denuders in the presence of ozone
KCl-coated denuders have become a standard method for measurement of gaseous oxidized mercury, but their performance has not been exhaustively evaluated, especially in field conditions. In this study, KCl-coated and uncoated quartz denuders loaded with HgCl<sub>2</sub> and HgBr<sub>2</sub> lost 29–55% of these compounds, apparently as elemental mercury, when exposed to ozone (range of 6–100 ppb tested). This effect was also observed for denuders loaded with gaseous oxidized mercury at a field site in Nevada (3–37% of oxidized mercury lost). In addition, collection efficiency decreased by 12–30% for denuders exposed to 50 ppb ozone during collection of HgCl<sub>2</sub>. While data presented were obtained from laboratory tests and as such do not exactly simulate field sampling conditions, these results indicate that the KCl denuder oxidized mercury collection method may not be as robust as previously thought. This work highlights needs for further testing of this method, clear identification of gaseous oxidized mercury compounds in the atmosphere, and development of field calibration methods for these compounds
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