1,042 research outputs found
The use of composite ferrocyanide materials for the treatment of high salinity liquid radioactive wastes rich in cesium isotopes
Several factors affecting the removal of cesium from LRW, namely total salt content, pH
and organic matter content, were also investigated. High concentrations of complexing organic matter
significantly reduced the sorption capacity of ferrocyanide sorbents
Hadron Spectroscopy with Dynamical Chirally Improved Fermions
We simulate two dynamical, mass degenerate light quarks on 16^3x32 lattices
with a spatial extent of 2.4 fm using the Chirally Improved Dirac operator. The
simulation method, the implementation of the action and signals of
equilibration are discussed in detail. Based on the eigenvalues of the Dirac
operator we discuss some qualitative features of our approach. Results for
ground state masses of pseudoscalar and vector mesons as well as for the
nucleon and delta baryons are presented.Comment: 26 pages, 17 figures, 10 table
Local and systemic metal ion release occurs intraoperatively during correction and instrumented spinal fusion for scoliosis
STUDY DESIGN: Prospective pilot study. OBJECTIVES: The aim of this study was to measure titanium, niobium and aluminium levels in various intraoperative and postoperative samples to determine patterns of metal ion release that occur within the first month following instrumented spinal fusion. Raised serum metal ion levels are reported following instrumented spinal fusion in adolescent idiopathic scoliosis. The exact topological origin and chronology of metal ion release remains conjectural. Recent literature suggests an immediate rise in serum metal levels within the first postoperative week. METHODS: Titanium, niobium and aluminium levels were measured before, during and after surgery in serum and local intraoperative fluid samples obtained from two pediatric patients undergoing posterior correction and instrumentation for scoliosis. RESULTS: Measurable metal ion levels were detected in all local samples obtained from wound irrigation fluid, cell saver blood, and fluid that immersed metal universal reduction screw tabs. Postoperative serum metal ion levels were elevated compared to baseline preoperative levels. In general, metal ion levels were considerably higher in the intraoperative fluid samples compared to those observed in the serum levels. CONCLUSION: Our findings of contextually high metal ion concentrations in intraoperative and early postoperative samples provide further empirical support of a 'putting-in' phenomenon of metal ion release following instrumented spinal fusion. This challenges existing beliefs that metal ion release occurs during an intermediate 'wearing-in' phase. We recommend thorough irrigation of the operative site prior to wound closure to dilute and remove intraoperative metal ion debris. Possibilities of filtering trace metal ions from cell saver content may be considered.William J. Cundy, Annika R. Mascarenhas, Georgia Antoniou, Brian J. C. Freeman, Peter J. Cund
Nucleon structure in terms of OPE with non-perturbative Wilson coefficients
Lattice calculations could boost our understanding of Deep Inelastic
Scattering by evaluating moments of the Nucleon Structure Functions. To this
end we study the product of electromagnetic currents between quark states. The
Operator Product Expansion (OPE) decomposes it into matrix elements of local
operators (depending on the quark momenta) and Wilson coefficients (as
functions of the larger photon momenta). For consistency with the matrix
elements, we evaluate a set of Wilson coefficients non-perturbatively, based on
propagators for numerous momentum sources, on a 24^3 x 48 lattice. The use of
overlap quarks suppresses unwanted operator mixing and lattice artifacts.
Results for the leading Wilson coefficients are extracted by means of Singular
Value Decomposition.Comment: 7 pages, 3 figures, contribution to the XXVI International Symposium
on Lattice Field Theory, July 14-19 Williamsburg, Virginia, US
High purity nanoparticles exceed stoichiometry limits in rebox chemistry: the nano way to cleaner water
A potentially cheaper and more effective way of cleaning wastewater has been discovered by scientists
at Nazarbayev University and the University of Brighton researching nanotechnology [1]. It is well
established that when particles are reduced to the nanoscale unexpected effects occur. Silver, for example,
interacts with mercury ions in a fixed ratio of atoms (stoichiometry), typically 2:1, which presents a limit
that has never been exceeded. In this project we used an alternative chemical procedure based on modified
quartz sand to immobilise silver nanoparticles (NPs) with control over their size. We found that when the
size of the silver NPs decreased below 35 nm the amount of mercury ions reacting with silver increased
beyond the long-held limit and rose to a maximum of 1:1.2 for 10 nm sized silver
High purity nanoparticles exceed stoichiometry limits in rebox chemistry: the nano way to cleaner water
A potentially cheaper and more effective way of cleaning wastewater has been discovered by scientists
at Nazarbayev University and the University of Brighton researching nanotechnology [1]. It is well
established that when particles are reduced to the nanoscale unexpected effects occur. Silver, for example,
interacts with mercury ions in a fixed ratio of atoms (stoichiometry), typically 2:1, which presents a limit
that has never been exceeded. In this project we used an alternative chemical procedure based on modified
quartz sand to immobilise silver nanoparticles (NPs) with control over their size. We found that when the
size of the silver NPs decreased below 35 nm the amount of mercury ions reacting with silver increased
beyond the long-held limit and rose to a maximum of 1:1.2 for 10 nm sized silver
Nucleon decay and atmospheric neutrinos in the Mont Blanc experiment
In the NUSEX experiment, during 2.8 years of operation, 31 fully contained events have been collected; 3 among them are nucleon decay candidates, while the others have been attributed to upsilon interactions. Limits on nucleon lifetime and determinations of upsilon interaction rates are presented
Late holocene tectonic land-level changes and tsunamis at mitla lagoon
Resumen Información sedimentológica, estratigráfica y geoquímica registra cambios abruptos de elevación, subsidencia de la costa y cambios en la salinidad de la laguna Mitla, que pueden estar asociados a un tsunami en 3400-3500 AP aproximadamente. Las observaciones son respaldadas por datos de microfósiles (polen, diatomeas y fitolitos) de otros estudios en la costa de Guerrero. Los datos de estratigrafía indican una tasa de sedimentación de aproximadamente 1mm/año. El registro del nivel del mar de corto plazo a partir de 1952 de datos de mareógrafos son comparados con el registro de largo plazo (del registro sedimentario, c. 3500 años AP) de la deformación cosísmica esperada en la costa. Los sismos grandes recientes ocurridos en la zona de subducción Mexicana central rompieron un área de ancho limitado, de aproximadamente ~60 km, pero algunos sismos prehistóricos pudieron romper la interfase de acoplamiento de placas completa hasta la trinchera, generando por tanto subsidencia costera significativa y probablemente un tsunami grande. Palabras clave: Cambios de nivel del mar, holoceno, sismos, tsunami, lagunas costeras tropicales, paleoambientes. Abstract Sedimentological, stratigraphic and geochemical data record abrupt land elevation change, coastal subsidence, and changes in the salinity of Mitla lagoon that may be associated with a tsunami around 3400-3500 yr BP. The observations are supported by microfossil data (pollen, diatoms and phytolith) from other studies on the Guerrero coast. Stratigraphic data indicate an average Late Holocene sedimentation rate of about 1 mm/yr. Shortterm sea-level records from 1952 of tide gauge data are compared with expected coseismic coastal deformation, and long-term records of coastal deformation from the sediment record c. 3500 yr BP. Recent large earthquakes in the Central Mexico subduction zone ruptured an area of limited width of about ~60 km, but some prehistoric earthquakes may have ruptured the entire coupled plate interface almost up to the trench, thus generating significant coastal subsidence and possibly a large tsunami
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