73 research outputs found
Feasibility of surveying pesticide coverage with airborne fluorometer
Response of a Fraunhofer line discriminator (FLD) to varying distributions of granulated corncobs stained with varying concentrations of Rhodamine WT dye was tested on the ground and from an H-19 helicopter. The granules are used as a vehicle for airborne emplacement of poison to control fire ants in the eastern and southeastern United States. Test results showed that the granules are detectable by FLD but that the concentration must be too great to be practical with the present apparatus. Possible methods for enhancement of response may include: (1) increasing dye concentration; (2) incorporating with the poisoned granules a second material to carry the dye alone; (3) use of a more strongly fluorescent substance (at 5890 A); (4) modifying the time interval after dyeing, or modifying the method of dyeing; (5) modifying the FLD for greater efficiency, increased field of view or larger optics; or (6) experimenting with laser-stimulated fluorescence
Test of airborne fluorometer over land surfaces and geologic materials
Response of an experimental Fraunhofer line discriminator to a wide range of surficial deposits common in deserts and semideserts was tested in the laboratory and from an H-19 helicopter. No signals attributable to fluorescence were recorded during 540 miles of aerial traverses over southeastern California and west-central Arizona. It was concluded that exposed surfaces of target materials throughout the traverses were either nonluminescent at 5890 A or not sufficiently so to be detectable. It cannot be ruled out that the lack of fluorescence is partly attributable to surficial coatings of nonluminescent weathered material. The principal route surveyed from the air was from Needles, California to Furnace Creek Ranch, Death Valley and return, via the Amargosa River valley, Silurian Lake (dry), Silver Lake (dry), and Soda Lake (dry). Principal targets traversed were unconsolidated clastic sediments ranging from silty clay to cobbles, and a wide range of evaporite deposits
Hydrogeology of Closed Basins and Deserts of South America, ERTS-1 Interpretations
Hydrogeology of closed basins and deserts of South America (Bolivia, Argentina, Chile, and Peru), ERTS-1 interpretation
Genus 2 Cantor sets
We construct a geometrically self-similar Cantor set of genus in
. This construction is the first for which the local genus is
shown to be at every point of . As an application, we construct, also
for the first time, a uniformly quasiregular mapping for which the Julia set is a genus Cantor set.Comment: 20 pages, 6 figure
Acid mine drainage in Southeastern Ohio
Originally prepared for the 1998 North-Central Section meeting of the Geological Society of America
POLLUTION SURVEILLANCE AND DATA ACQUISITION USING MULTISPECTRAL REMOTE SENSING 1
Large scale water resource investigations and effective pollution surveillance programs require the development of additional instrumentation and techniques to supplement existing methods of data acquisition. As a result, interest is growing in the concept of remote sensing. Described in this paper is the multispectral sensor concept and its application in water resource studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73841/1/j.1752-1688.1970.tb01651.x.pd
Educating a New Generation of Doctors to Improve the Health of Populations in Low- and Middle-Income Countries
Francesca Celletti and colleagues from WHO argue that a transformation in the scale-up of medical education in low- and middle-income countries is needed, and detail what this might look like
Changes in macroinvertebrate community structure provide evidence of neutral mine drainage impacts
Contamination of aquatic environments as a consequence of metal mining is an international issue. Most
historic studies have considered the impact of acid mine drainage (pH < 6) on instream communities and
comparatively little attention has been given to sites where drainage is typically circum-neutral (6 > pH < 8).
Here, the impacts of historic mining activities on the benthic macroinvertebrate community of a circumneutral
river in Central Wales are assessed. Biotic and diversity indices, widely used for biomonitoring
purposes, indicate aquatic macroinvertebrate assemblages within the Afon Twymyn to be in a good
condition, despite severe metal contamination of bed sediments and river water. However, Canonical
Correspondence Analysis identifies differences in community structure between mining impacted and
unimpacted reaches of the river associated with chalcophile (Zn, Pb, Cu, Cd) and common (Fe and Mn)
metals. Stream pH was not a significant factor structuring the macroinvertebrate community. Widely
utilised macroinvertebrate indices failed to identify impacts at the community level because they either
seek to identify impacts of a specific contaminant or are dependent on a model community response to
a given stress. The nature of metal mine discharges is temporally complex, having highly variable
chemical signatures and as a result, care is advised when interpreting and modelling community
impacts. The use of standard macroinvertebrate biotic and diversity indices in the context of the EU
Water Framework Directive could lead to erroneous classifications of aquatic ecosystem health when
used for bio-monitoring rivers affected by neutral mine drainage where other indicators are unavailable
Knowlton Circles: A Later Neolithic and Early Bronze Age Ceremonial Complex and Its Environs—A Review
The larger henge monuments of Wessex have been the focus of detailed archaeological investigation for over a century and consequently their study has provided a greater, albeit fragmentary, understanding of later Neolithic society. For the most part such studies have continued to show that these great mega-structures of the third millennium B.C. persist as beacons of ceremonial functionality into which later societies invested much of themselves, intellectually, spiritually and unquestionably physically. While Stonehenge, Avebury and Durrington Walls continue to attract a great deal of attention with ongoing research, comparable sites in Dorset have been less well researched. Two campaigns of archaeological investigation undertaken in the Allen Valley of east Dorset by the author have focussed upon the complex of earthworks at Knowlton and additionally at one of three broadly contemporary barrow cemeteries located nearby. The findings from these investigations are beginning to shed more light on the possible origins and development of these important but weakly understood landscapes. This paper outlines some of the main findings from these investigations and posits a chronological framework for the integration of a group of monuments that formed both a ceremonial landscape and a geographical and spiritual home for communities that lasted for a thousand years
- …