1,108 research outputs found
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Analysis of components from drip tests with ATM-10 glass
Waste package assemblies consisting of actinide-doped West Valley ATM-10 reference glass and sensitized 304L stainless steel have been reacted with simulated repository groundwater using the Unsaturated Test Method. Analyses of surface corrosion and reaction products resulting from tests that were terminated at scheduled intervals between 13 and 52 weeks are reported. Analyses reveal complex interactions between the groundwater, the sensitized stainless steel waste form holder, and the glass. Alteration phases form that consist mainly of smectite clay, brockite, and an amorphous thorium iron titanium silicate, the latter two incorporating thorium, uranium, and possibly transuranics. The results from the terminated tests, combined with data from tests that are still ongoing, will help determine the suitability of glass waste forms in the proposed high-level repository at the Yucca Mountain Site
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Solution-borne colloids from drip tests using actinide-doped and fully-radioactive waste glasses
Drip tests designed to replicate the synergistic interactions between waste glass, repository groundwater, water vapor, and sensitized 304L stainless steel in the potential Yucca Mountain Repository have been ongoing in our laboratory for over ten years. Results will be presented from three sets of these drip tests: two with actinide-doped glasses, and one with a fully-radioactive glass. Periodic sampling of these tests have revealed trends in actinide release behavior that are consistent with their entrainment in colloidal material when as-cast glass is reacted. Results from vapor hydrated glass show that initially the actinides are completely dissolved in solution, but as the reaction proceeds, the actinides become suspended in solution. Sequential filtering and alpha spectroscopy of colloid-bearing leachate solutions indicate that more than 80 percent of the plutonium and americium are bound to particles that are captured by a 0. 1 gm filter, while less than 10 percent of the neptunium is stopped by a 0. 1 gm filter. Analytical transmission electron microscopy has been used to examine particles from leachate solutions and to identify several actinide-bearing phases which are responsible for the majority of actinide release during glass corrosion
EPUAP classification system for pressure ulcers: European reliability study
‘The definitive version is available at www3.interscience.wiley.com .' Copyright Blackwell PublishingPeer reviewe
Classification of graph C*-algebras with no more than four primitive ideals
We describe the status quo of the classification problem of graph C*-algebras
with four primitive ideals or less
Polynomial-Time Amoeba Neighborhood Membership and Faster Localized Solving
We derive efficient algorithms for coarse approximation of algebraic
hypersurfaces, useful for estimating the distance between an input polynomial
zero set and a given query point. Our methods work best on sparse polynomials
of high degree (in any number of variables) but are nevertheless completely
general. The underlying ideas, which we take the time to describe in an
elementary way, come from tropical geometry. We thus reduce a hard algebraic
problem to high-precision linear optimization, proving new upper and lower
complexity estimates along the way.Comment: 15 pages, 9 figures. Submitted to a conference proceeding
Fish heating tolerance scales similarly across individual physiology and populations
Extrapolating patterns from individuals to populations informs climate vulnerability models, yet biological responses to warming are uncertain at both levels. Here we contrast data on the heating tolerances of fishes from laboratory experiments with abundance patterns of wild populations. We find that heating tolerances in terms of individual physiologies in the lab and abundance in the wild decline with increasing temperature at the same rate. However, at a given acclimation temperature or optimum temperature, tropical individuals and populations have broader heating tolerances than temperate ones. These congruent relationships implicate a tight coupling between physiological and demographic processes underpinning macroecological patterns, and identify vulnerability in both temperate and tropical species
Froth-like minimizers of a non local free energy functional with competing interactions
We investigate the ground and low energy states of a one dimensional non
local free energy functional describing at a mean field level a spin system
with both ferromagnetic and antiferromagnetic interactions. In particular, the
antiferromagnetic interaction is assumed to have a range much larger than the
ferromagnetic one. The competition between these two effects is expected to
lead to the spontaneous emergence of a regular alternation of long intervals on
which the spin profile is magnetized either up or down, with an oscillation
scale intermediate between the range of the ferromagnetic and that of the
antiferromagnetic interaction. In this sense, the optimal or quasi-optimal
profiles are "froth-like": if seen on the scale of the antiferromagnetic
potential they look neutral, but if seen at the microscope they actually
consist of big bubbles of two different phases alternating among each other. In
this paper we prove the validity of this picture, we compute the oscillation
scale of the quasi-optimal profiles and we quantify their distance in norm from
a reference periodic profile. The proof consists of two main steps: we first
coarse grain the system on a scale intermediate between the range of the
ferromagnetic potential and the expected optimal oscillation scale; in this way
we reduce the original functional to an effective "sharp interface" one. Next,
we study the latter by reflection positivity methods, which require as a key
ingredient the exact locality of the short range term. Our proof has the
conceptual interest of combining coarse graining with reflection positivity
methods, an idea that is presumably useful in much more general contexts than
the one studied here.Comment: 38 pages, 2 figure
Complementarity of information sent via different bases
We discuss quantitatively the complementarity of information transmitted by a
quantum system prepared in a basis state in one out of several different
mutually unbiased bases (MUBs). We obtain upper bounds on the information
available to a receiver who has no knowledge of which MUB was chosen by the
sender. These upper bounds imply a complementarity of information encoded via
different MUBs and ultimately ensure the security in quantum key distribution
protocols.Comment: 9 pages, references adde
Stressful life events, intimate partner violence, and perceived stress in the postpartum period: longitudinal findings in rural Pakistan
Purpose: While the association between intimate partner violence (IPV) and stress is well documented, the directionality of this relationship is unclear. We use an adjusted longitudinal study design to better understand if stressful life events in the home precipitate or exacerbate intimate partner violence (IPV) and if experiences of IPV, in turn, increase levels of perceived stress. Methods: Longitudinal data were collected among married women in rural Pakistan at 12 and 24 months postpartum (N = 815). Adjusted Poisson and linear regression models were used to examine stressful life events, past year IPV and severity (number and frequency of violent acts), and perceived stress (Cohen Perceived Stress Scale). Results: At 12 months postpartum, the prevalence of past year physical, psychological, and sexual IPV was 8.5%, 25.7%, and 25.1%, respectively, with 42.6% experiencing any IPV. After adjustment, stressful life events were associated with a subsequent increased likelihood of all IPV types and increased severity of all but physical IPV. Any past year IPV (versus none) and greater IPV severity were associated with 3.43 (95% CI 2.33–4.52) and 2.57 (95% CI 1.87–3.27) point subsequent increases in perceived stress. Physical, psychological, and sexual IPV and their respective severities were all independently associated with increased perceived stress. Conclusions: Among postpartum women in Pakistan, stressful life events increase the likelihood of IPV and, in turn, experiences of IPV increase stress levels. Support to families undergoing stressful circumstances may be critical to reducing women’s IPV exposure and resulting elevated stress
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