2,757 research outputs found
Public contracts as accountability mechanisms: assuring quality in public healthcare in England and Wales
Contracting in the public sector is designed to enhance the accountability of service providers to their funders. The idea is that quality is improved by the use of service specifications, monitoring of performance and imposition of contractual sanctions. Socio-legal and economic theories of contract indicate that it will be difficult to make and enforce contracts to achieve this. The results of a study of National Health Services contracting in England and Wales are reported. We conclude that contracts alone are not sufficient to improve accountability – collibration of various regulatory measures (including more hierarchical mechanisms such as performance targets) is required
Engineering Properties of Overburden Materials for the Means Project
A geotechnical investigation was performed to determine the physical properties (classification) and engineering properties of the overburden material from a proposed oil shale mining site in Montgomery County (Means Project). Three overburden materials were received in sealed meal drums and were labeled Nancy Member, Borden Formation; Clay City Bed, Farmers Member, Borden Formation; and Henley bed, Farmers Member, Borden Formation. Hereafter, they will be referred to as the Nancy, Clay City and Henley, respectively. the various types of geotechnical laboratory tests performed on these materials are listed in Table 1
Engineering Properties of Two Spent Shales and Minus 1/4-Inch Raw Shale for the Means Project
A geotechnical investigation was performed to determine the physical properties (classification) and engineering properties of the Sunbury oil shale from a proposed oil shale mining site in Montgomery County (Means Project). Three materials were recieved in sealed metal drums and were labeled Raw Oil Shale (only material less than 0.25 inch), Sunbury, spent shale, and Sunbury shale (2.5-inch to 1/4-inch). The material labeled Sunbury, spent shale, (hereafter referred to as Spent Shale No. 1), has very little fines and the particles were angular in shape. The Sunbury, spent shale, 2.5-inch to 0.25 inch, (hereafter referred to as Spent Shale No. 2), was subangular or rounded in shape. The various types of geotechnical laboratory tests performed on these materials are listed in Table 1
Engineering Properties of Kentucky Oil Shales
Excavation, handling, and the environmentally safe disposal of spent oil shale and overburden materials require a knowledge of their geotechnical engineering properties. To determine these properties a laboratory investigation of the physical and geotechnical engineering properties was made. The physical tests consisted of mechanical analyses, Atterberg Limits, and specific gravity determinations. Geotechnical properties were determined by moisture-density analyses, triaxial compression, permeability tests, slake-durability, one-dimensional compression tests, and Los Angeles abrasion. A one-dimensional compression test was devised to address the problem of placement, loading, and saturation of the spent shales and overburden materials. The compacted, unprocessed oil shales were more susceptible to inundation and compression than compacted specimens of retorted shales and chars. Comparisons of the geotechnical properties of the unprocessed oil shales and processed shales are made
Generalized Rosenfeld scalings for tracer diffusivities in not-so-simple fluids: Mixtures and soft particles
Rosenfeld [Phys. Rev. A 15, 2545 (1977)] noticed that casting transport
coefficients of simple monatomic, equilibrium fluids in specific dimensionless
forms makes them approximately single-valued functions of excess entropy. This
has predictive value because, while the transport coefficients of dense fluids
are difficult to estimate from first principles, excess entropy can often be
accurately predicted from liquid-state theory. Here, we use molecular
simulations to investigate whether Rosenfeld's observation is a special case of
a more general scaling law relating mobility of particles in mixtures to excess
entropy. Specifically, we study tracer diffusivities, static structure, and
thermodynamic properties of a variety of one- and two-component model fluid
systems with either additive or non-additive interactions of the hard-sphere or
Gaussian-core form. The results of the simulations demonstrate that the effects
of mixture concentration and composition, particle-size asymmetry and
additivity, and strength of the interparticle interactions in these fluids are
consistent with an empirical scaling law relating the excess entropy to a new
dimensionless (generalized Rosenfeld) form of tracer diffusivity, which we
introduce here. The dimensionless form of the tracer diffusivity follows from
knowledge of the intermolecular potential and the transport / thermodynamic
behavior of fluids in the dilute limit. The generalized Rosenfeld scaling
requires less information, and provides more accurate predictions, than either
Enskog theory or scalings based on the pair-correlation contribution to the
excess entropy. As we show, however, it also suffers from some limitations,
especially for systems that exhibit significant decoupling of individual
component tracer diffusivities.Comment: 15 pages, 10 figure
Cosmic string loops and large-scale structure
We investigate the contribution made by small loops from a cosmic string
network as seeds for large-scale structure formation. We show that cosmic
string loops are highly correlated with the long-string network on large scales
and therefore contribute significantly to the power spectrum of density
perturbations if the average loop lifetime is comparable to or above one Hubble
time. This effect further improves the large-scale bias problem previously
identified in earlier studies of cosmic string models.Comment: 5 pages, 5 figure
Shear strength properties of wet granular materials
We investigate shear strength properties of wet granular materials in the
pendular state (i.e. the state where the liquid phase is discontinuous) as a
function of water content. Sand and glass beads were wetted and tested in a
direct shear cell and under various confining pressures. In parallel, we
carried out three-dimensional molecular dynamics simulations by using an
explicit equation expressing capillary force as a function of interparticle
distance, water bridge volume and surface tension. We show that, due to the
peculiar features of capillary interactions, the major influence of water
content over the shear strength stems from the distribution of liquid bonds.
This property results in shear strength saturation as a function of water
content. We arrive at the same conclusion by a microscopic analysis of the
shear strength. We propose a model that accounts for the capillary force, the
granular texture and particle size polydispersity. We find fairly good
agreement of the theoretical estimate of the shear strength with both
experimental data and simulations. From numerical data, we analyze the
connectivity and anisotropy of different classes of liquid bonds according to
the sign and level of the normal force as well as the bond direction. We find
that weak compressive bonds are almost isotropically distributed whereas strong
compressive and tensile bonds have a pronounced anisotropy. The probability
distribution function of normal forces is exponentially decreasing for strong
compressive bonds, a decreasing power-law function over nearly one decade for
weak compressive bonds and an increasing linear function in the range of
tensile bonds. These features suggest that different bond classes do not play
the same role with respect to the shear strength.Comment: 12 page
A targeted gene panel that covers coding, non-coding and short tandem repeat regions improves the diagnosis of patients with neurodegenerative diseases
Genetic testing for neurodegenerative diseases (NDs) is highly challenging because of genetic heterogeneity and overlapping manifestations. Targeted-gene panels (TGPs), coupled with next-generation sequencing (NGS), can facilitate the profiling of a large repertoire of ND-related genes. Due to the technical limitations inherent in NGS and TGPs, short tandem repeat (STR) variations are often ignored. However, STR expansions are known to cause such NDs as Huntington\u27s disease and spinocerebellar ataxias type 3 (SCA3). Here, we studied the clinical utility of a custom-made TGP that targets 199 NDs and 311 ND-associated genes on 118 undiagnosed patients. At least one known or likely pathogenic variation was found in 54 patients; 27 patients demonstrated clinical profiles that matched the variants; and 16 patients whose original diagnosis were refined. A high concordance of variant calling were observed when comparing the results from TGP and whole-exome sequencing of four patients. Our in-house STR detection algorithm has reached a specificity of 0.88 and a sensitivity of 0.82 in our SCA3 cohort. This study also uncovered a trove of novel and recurrent variants that may enrich the repertoire of ND-related genetic markers. We propose that a combined comprehensive TGPs-bioinformatics pipeline can improve the clinical diagnosis of NDs
The Artist as Philanthropist: Strengthening the Next Generation of Artist-Endowed Foundations, Study Report Supplement 2013
This new publication presents updated findings of the Aspen Institute National Study of Artist-Endowed Foundations, reflecting the field's continued growth since release of the Study's initial findings based on 2005 data. Drawing on new data through 2010, Study Report Supplement 2013 details this growth, analyzes factors shaping it, and explores ramifications for foundation practice. Appendices list identified foundations and present data profiles of those reporting assets of at least $1 million. New briefing papers address rising topics that will influence the field's development and a descriptive survey summarizes estate planning literature as it pertains to visual artists
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