2,401 research outputs found
Progressive Assessment of Lake Depths in Cedar Lake
Cedar Lake on the campus of Cedarville University (CU) has a history that probably does not match what the original developers had envisioned. At present, the lake is the visual focal point of the campus and people often ask about its physical characteristics. The questioned characteristics include, but are not limited to, water depth, bottom configuration, water volume, drainage area that feeds it, rate of infilling, perimeter length, and lake surface area. This study considers the issues of potential changes in water depth, bottom configuration, and lake volume over an extended period of time, and further considers what to use as baseline data to start a long-term assessment. Changes to water depth, bottom configuration, and water volume in any lake are most often attributed to sediment infilling unless observed purposeful alteration by man is known to have occurred. A comparison of changes in total water volume of Cedar Lake will probably be the most valuable means by which the rate of infilling can be assessed.
In the fall of 2012 the CU Environmental Geology class did an assignment which produced a bottom-contour map of Cedar Lake. Although the depth and position measurement techniques were somewhat crude, the end result was a map that seemed to be a very reasonable depiction on the lake bottom configuration. With certain refinements to the field techniques and the equipment, a second map will be produced in the fall of 2014. After that, a new map would be created every other year in the fall from new field data. The project should continue for a minimum of ten years. A software package called Surfer was used in 2012 and will continue to be used to produce the contour maps of the lake and to do the volume calculations.
Ultimately, if techniques and assessments are deemed adequate, then conclusions can be made regarding the infilling rate of the lake. Rate-of-infilling is a condition that needs to be understood in order to address both the short- and long-term health of the lake. The economic consequences may be minor or significant depending on the findings
Introduction to papers on astrostatistics
We are pleased to present a Special Section on Statistics and Astronomy in
this issue of the The Annals of Applied Statistics. Astronomy is an
observational rather than experimental science; as a result, astronomical data
sets both small and large present particularly challenging problems to analysts
who must make the best of whatever the sky offers their instruments. The
resulting statistical problems have enormous diversity. In one problem, one may
have to carefully quantify uncertainty in a hard-won, sparse data set; in
another, the sheer volume of data may forbid a formally optimal analysis,
requiring judicious balancing of model sophistication, approximations, and
clever algorithms. Often the data bear a complex relationship to the underlying
phenomenon producing them, much in the manner of inverse problems.Comment: Published in at http://dx.doi.org/10.1214/09-AOAS234 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Estimates of Maximum Past Overburden for the Pierre Shale, Hayes Area, South Dakota
The Pierre Shale of the Northern Great Plains area of the United State is an Upper Cretaceous shale which was deposited in a marine environment. Geotechnically, the shale has been classified as an overconsolidated clay-shale. In South Dakota the Pierre Shale crops out extensively in the central and western portions of the state.
In this study an investigation was conducted for the purpose of clarifying and examining the existence of a discrepancy between geotechnically and geologically derived estimates of maximum past overburden for the Pierre Shale at Hayes, South Dakota.
The geological determination involved examining the topographic high points of Central South Dakota for the purpose of locating the remnants of any Tertiary rock that may have existed in the area. Based on this field evidence, a geologic profile showing estimated thickness of former strata in the area was constructed and the maximum thickness of past overburden was estimated for the Hayes study site.
The geotechnical determination was made by conducting laboratory high-pressure consolidation tests on samples from cores from Hayes. Preconsolidation pressures were estimated from the consolidation curves and the values were converted to thickness of overburden.
The geological determination of the maximum thickness of past overburden indicates that 600 to 1100 feet (183 to 3 3 5 m) of Tertiary rock and Cretaceous Pierre Shale has been removed by erosion at the Hayes site. Geotechnically, the preconsolidation pressures indicate that 3600 to 5000 feet (1100 to 1525 m) of material has been removed. The discrepancy that exists between the geological and geotechnical determinations is considered significant.
Because it was believed the geotechnical estimate was too high instead of the geological too low, the search for the cause of the discrepancy centered on those factors known to affect the determination of the preconsolidation pressure, Pc.
Laboratory factors were ruled out because their affect is to reduce the estimated Pc, thus reducing the discrepancy. Of the geological factors that are known to increase Pc, only two warranted assessment in this study --cementation and delayed consolidation. By default, these two mechanisms appear to be the possible causes for the discrepancy
Extraction of pigment from plant material
The present invention is directed to a process for extracting pigments, namely carotenoids, from plant material. The process includes the step of combining shredded plant material with an enzyme. The enzyme breaks down the plants cellular walls releasing the carotenoids contained within the plant cells. The enzyme added to the plant material can be pectinase, cellulase, hemicellulase, or mixtures thereof
Geotechnical Properties and Slope Stability Analysis of Surficial Sediments on the Baltimore Canyon Continental Slope: U.S. Geological Survey Open-File Report 81-733
Geotechnical properties and slope stability analysis of surficial sediments on the Georges Bank Continental Slope: U.S. Geological Survey Open-File Report 81-566
So, You Want to 3D Print a Landscape? An Outline of Some Methods
https://digitalcommons.cedarville.edu/alum_books/1453/thumbnail.jp
So, You Want to 3D Print a Landscape? An Outline of Some Methods
https://digitalcommons.cedarville.edu/alum_books/1435/thumbnail.jp
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