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Treatment methods for radioactive mixed wastes in commercial low-level wastes: technical considerations
Treatment options for the management of three generic categories of radioactive mixed waste in commercial low-level wastes (LLW) have been identified and evaluated. These wastes were characterized as part of a BNL study in which LLW generators were surveyed for information on potential chemical hazards in their wastes. The general treatment options available for mixed wastes are destruction, immobilization, and reclamation. Solidification, absorption, incineration, acid digestion, wet-air oxidation, distillation, liquid-liquid wastes. Containment, segregation, decontamination, and solidification or containment of residues, have been considered for lead metal wastes which have themselves been contaminated and are not used for purposes of waste disposal shielding, packaging, or containment. For chromium-containing wastes, solidification, incineration, wet-air oxidation, acid digestion, and containment have been considered. For each of these wastes, the management option evaluation has included an assessment of testing appropriate to determine the effect of the option on both the radiological and potential chemical hazards present
Light Quark Mass Determinations from the Lattice
This paper is a review of recent lattice determinations of the light quark
masses. It describes the method employed to calculate quark masses in the
lattice formulation, and the extrapolations required to reach the physical
regime. This review is designed to be accessible to a general audience, not
specifically lattice theorists.Comment: Invited review talk at QCD97, Montpellier (July '97). 8 pages, 2
figures. Requires espcrc2.sty Minor changes: a reference added and a table
updated accordingl
A Tale of Two Fractals: The Hofstadter Butterfly and The Integral Apollonian Gaskets
This paper unveils a mapping between a quantum fractal that describes a
physical phenomena, and an abstract geometrical fractal. The quantum fractal is
the Hofstadter butterfly discovered in 1976 in an iconic condensed matter
problem of electrons moving in a two-dimensional lattice in a transverse
magnetic field. The geometric fractal is the integer Apollonian gasket
characterized in terms of a 300 BC problem of mutually tangent circles. Both of
these fractals are made up of integers. In the Hofstadter butterfly, these
integers encode the topological quantum numbers of quantum Hall conductivity.
In the Apollonian gaskets an infinite number of mutually tangent circles are
nested inside each other, where each circle has integer curvature. The mapping
between these two fractals reveals a hidden threefold symmetry embedded in the
kaleidoscopic images that describe the asymptotic scaling properties of the
butterfly. This paper also serves as a mini review of these fractals,
emphasizing their hierarchical aspects in terms of Farey fractions
The Leptonic Decay Constants of Mesons and the Lattice Resolution
We present a high statistics study of the leptonic decay constant of
heavy pseudoscalar mesons using propagating heavy Wilson quarks within the
quenched approximation, on lattices covering sizes from about 0.7~fm to 2~fm.
Varying between 5.74 and 6.26 we observe a sizeable dependence of
when one uses the quark field normalization that was suggested by
Kronfeld and Mackenzie, compared with the weaker dependence observed for the
standard relativistic norm. The two schemes come into agreement when one
extrapolates to . The extrapolations needed to reach the
continuum quantity introduce large errors and lead to the value
~GeV in the quenched approximation. This suggests that much more
effort will be needed to obtain an accurate lattice prediction for .Comment: 11 pages Latex + 5 tables + 8 postscript figures, unix shell archive,
DESY preprint DESY 93-17
Impurity and interface bound states in and superconductors
Motivated by recent discoveries of novel superconductors such as
NaCoOHO and SrRuO, we analysize features of
quasi-particle scattering due to impurities and interfaces for possible gapful
and Cooper pairing. A bound state appears near
a local impurity, and a band of bound states form near an interface. We
obtained analytically the bound state energy, and calculated the space and
energy dependent local density of states resolvable by high-resolution scanning
tunnelling microscopy. For comparison we also sketch results of impurity and
surface states if the pairing is nodal p- or d-wave.Comment: 4 pages, 4 figure
Phenomenological Determination of the Beauty Meson Decay Parameter and the CP-Violating Angle
We fit the -matrix to all recent data with the following free
parameters: three mixing angles, the CP-violating angle in the Maiani
parametrisation, the top quark mass , and the product f_B{\cal
B}_{\B}^{1/2}, where is the -meson decay parameter and {\cal
B}_{\B} is the bag parameter. Our fits span a contiguous region in the
(f_B{\cal B}_{\B}^{1/2},\ \cos\delta)--plane, limited by 0.117\lsim f_B{\cal
B}_{\B}^{1/2}/{\rm GeV}\lsim 0.231 and --0.95 \lsim \lsim
0.70. The parameters f_B{\cal B}_{\B}^{1/2} and are strongly
positively correlated.Comment: 9 pages + 1 figure available upon request, HU-TFT-94-3
Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma.
Sentinel-lymph-node biopsy is associated with increased melanoma-specific survival (i.e., survival until death from melanoma) among patients with node-positive intermediate-thickness melanomas (1.2 to 3.5 mm). The value of completion lymph-node dissection for patients with sentinel-node metastases is not clear.
In an international trial, we randomly assigned patients with sentinel-node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph-node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma-specific survival. Secondary end points included disease-free survival and the cumulative rate of nonsentinel-node metastasis.
Immediate completion lymph-node dissection was not associated with increased melanoma-specific survival among 1934 patients with data that could be evaluated in an intention-to-treat analysis or among 1755 patients in the per-protocol analysis. In the per-protocol analysis, the mean (±SE) 3-year rate of melanoma-specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log-rank test) at a median follow-up of 43 months. The rate of disease-free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log-rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log-rank test); these results must be interpreted with caution. Nonsentinel-node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group.
Immediate completion lymph-node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma-specific survival among patients with melanoma and sentinel-node metastases. (Funded by the National Cancer Institute and others; MSLT-II ClinicalTrials.gov number, NCT00297895 .)
Non-volant small mammals at an Atlantic forest area situated nearby a limestone quarry (Limeira quarry), state of São Paulo, Brazil
Avanços recentes em nutrição de larvas de peixes
Os requisitos nutricionais de larvas de peixes são ainda mal compreendidos, o que leva a altas mortalidades
e problemas de qualidade no seu cultivo. Este trabalho pretende fazer uma revisão de novas metodologias de investigação, tais
como estudos com marcadores, genómica populacional, programação nutricional, génomica e proteómica funcionais, e
fornecer ainda alguns exemplos das utilizações presentes e perspectivas futuras em estudos de nutrição de larvas de peixes
Global carbonate accumulation from 145 Ma to Present (Cretaceous-Cenozoic): a new continental-scale analysis
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