5,337 research outputs found
Physical and Chemical Controls on Suffosion Development in Gypsic Soil, Culberson County, Texas
In the Gypsum Plain, suffosion processes have encouraged road failure through dissolution and transport of gypsic soils; however, no prior research has been conducted within the Delaware Basin in regard to these processes. These phenomena were evaluated in both field and laboratory settings in order to assess the parameters of suffosion development associated with Ranch to Market (RM) 652 in Culberson County, Texas, where infrastructure extends across Castile and Rustler strata. Field studies simulated surficial ponding in various gypsic soils and correlated suffosion potential with soil composition and thickness. Soluble fractions of gypsic soils were delineated through geochemical analyses, further expanding upon the soil descriptions published in the Culberson County Soil Survey (USDA, 2013). Suffosion modeling replicated processes observed in the field through repeated infiltration of Dellahunt and Elcor soils—soil piping and subsidence were induced within suffosion models. Lineaments inferred as solutional fractures were delineated using color infrared (CIR) images to determine regional suffosion potential.
Results obtained from this research were used to form a conceptual model of suffosion development in order to better mitigate damage imposed on infrastructure in evaporite karst terrains. Regions with thick, heterogeneous soils of low to moderate gypsum content (10-70%) and moderate fracture densities (100-800 m/km2) are optimal for suffosion development. This model should be considered for future projects in not only the Gypsum Plain, but for other arid environments with significant evaporite karst and gypsic soils as well
Legal Aid in Illinois: Selected Social and Economic Benefits
This study estimates the economic benefits of cases closed by seven legal aid providers in 2010. It also provides a picture of the level of economic disadvantage experienced by clients who benefited from legal aid using data on clients' average household size and income
Myelination: all about Rac n roll.
During the development of the peripheral nervous system, Schwann cells select individual axons from a nerve bundle and establish a one-to-one relationship through a process termed radial sorting. Recent findings identify the Rho family GTPase Rac1 as the downstream effector molecule responsible for process extension and lamellipodia formation in Schwann cells, allowing for proper radial sorting and myelination. These findings begin to shed light on our understanding of the distinct and yet essential molecular mechanisms involved in developmental processes preceding myelination
Kronecker coefficients for one hook shape
We give a positive combinatorial formula for the Kronecker coefficient
g_{lambda mu(d) nu} for any partitions lambda, nu of n and hook shape mu(d) :=
(n-d,1^d). Our main tool is Haiman's \emph{mixed insertion}. This is a
generalization of Schensted insertion to \emph{colored words}, words in the
alphabet of barred letters \bar{1},\bar{2},... and unbarred letters 1,2,.... We
define the set of \emph{colored Yamanouchi tableaux of content lambda and total
color d} (CYT_{lambda, d}) to be the set of mixed insertion tableaux of colored
words w with exactly d barred letters and such that w^{blft} is a Yamanouchi
word of content lambda, where w^{blft} is the ordinary word formed from w by
shuffling its barred letters to the left and then removing their bars. We prove
that g_{lambda mu(d) nu} is equal to the number of CYT_{lambda, d} of shape nu
with unbarred southwest corner.Comment: 37 pages, 3 figure
Three-Dimensional Solvable Artin Representations Ramified at One Prime
We classify the possibilities for the fixed field of the kernel of an
irreducible three-dimensional Artin representation of \Q with solvable image
ramified at one prime by using the classification of the finite irreducible
subgroups of \PGL_3(\C). This allows us to bound the number of such
representations with given Artin conductor
The toric ideal of a graphic matroid is generated by quadrics
Describing minimal generating sets of toric ideals is a well-studied and
difficult problem. Neil White conjectured in 1980 that the toric ideal
associated to a matroid is generated by quadrics corresponding to single
element symmetric exchanges. We give a combinatorial proof of White's
conjecture for graphic matroids.Comment: 19 pages, 4 figure
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