[en] The measurement of the branching fraction of the flavor changing neutral current B → X_sγ transition can be used to expose physics outside the Standard Model. In order to make a precise measurement of this inclusive branching fraction, it is necessary to be able to effectively separate signal and background in the data. In order to achieve better separation, an algorithm based on Boosted Decision Trees (BDTs) is implemented. Using Monte Carlo simulated events, ''forests'' of trees were trained and tested with different sets of parameters. This parameter space was studied with the goal of maximizing the figure of merit, Q, the measure of separation quality used in this analysis. It is found that the use of 1000 trees, with 100 values tested for each variable at each node, and 50 events required for a node to continue separating give the highest figure of merit, Q = 18.37

[en] Fluor Fernald, Inc. (Fluor Fernald), the contractor for the U. S. Department of Energy (DOE) Fernald Environmental Management Project (FEMP), recently submitted a new baseline plan for achieving site closure by the end of calendar year 2006. This plan was submitted at DOE's request, as the FEMP was selected as one of the sites for their accelerated closure initiative. In accordance with the accelerated baseline, the FEMP Waste Management Project (WMP) is actively evaluating innovative processes for the management and disposition of low-level uranium, fissile material, and thorium, all of which have been classified as waste. These activities are being conducted by the Low Level Waste (LLW) and Uranium Waste Disposition (UWD) projects. Alternatives associated with operational processing of individual waste streams, each of which poses potentially unique health physics, industrial hygiene and industrial hazards, are being evaluated for determination of the most cost effective and safe met hod for handling and disposition. Low-level Mixed Waste (LLMW) projects are not addressed in this paper. This paper summarizes historical uranium recycling programs and resultant trace quantity contamination of uranium waste streams with radionuclides, other than uranium. The presentation then describes how waste characterization data is reviewed for radiological and/or chemical hazards and exposure mitigation techniques, in conjunction with proposed operations for handling and disposition. The final part of the presentation consists of an overview of recent operations within LLW and UWD project dispositions, which have been safely completed, and a description of several current operations

[en] Purpose: To study the relationship between the severity of late reactions to radiotherapy in breast cancer patients, and the extent of residual radiation-induced DNA damage, using a rapid assay of keratinocytes obtained directly from skin biopsies. Methods and Materials: A review was made of 32 patients with breast cancer, treated uniformly by radiotherapy between 1983 and 1988, following breast-conserving surgery. Their late radiotherapy reactions were scored (9-14 years post-radiotherapy) using a modified LENT SOMA scale, and a 5-mm buttock skin punch biopsy was obtained. Intact skin was irradiated at room temperature, and after allowing 24 h for repair, the tissue was disaggregated and the cells processed for pulsed field gel electrophoresis (PFGE). Residual DNA damage was expressed as the fraction of DNA released (FDR) following 150 Gy. Results: Studies using flow cytometry on disaggregated breast skin showed that over 90% of the cells were keratinocytes. The PFGE assay was robust with low background FDRs in unirradiated skin samples (mean 3.2%) and a wide range of FDRs following irradiation from 11.5% to 26.6%. No correlation was found between the FDR at 150 Gy (FDR 150) and any of the late reaction scores or retrospective acute reaction scores. There was, however, a borderline significant correlation for family history and FDR 150 (p = 0.059). Conclusion: Rapid measurement of residual DNA damage in irradiated differentiated keratinocytes, the predominant cell population in skin biopsies, showed no correlation with the severity of symptomatic early or documented late reactions in a retrospectively studied group of 32 breast cancer patients

[en] The crystal structure of a light-harvesting protein that interacts with photosystem II is reported. Cyanobacteria and red algae use light-harvesting pigments bound by proteins to capture solar radiation and to channel excitation energy into their reaction centres. In most cyanobacteria, a multi-megadalton soluble structure known as the phycobilisome is a major light-harvesting system. Allophycocyanin is the main component of the phycobilisome core, forming a link between the rest of the phycobilisome and the reaction-centre core. The crystal structure of allophycocyanin from Thermosynechococcus elongatus (TeAPC) has been determined and refined at 3.5 Å resolution to a crystallographic R value of 26.0% (R_free = 28.5%). The structure was solved by molecular replacement using the allophycocyanin structure from Spirulina platensis as the search model. The asymmetric unit contains an (αβ) monomer which is expanded by symmetry to a crystallographic trimer

[en] Highlights: • First report of crystalline Fe₂O₃/Fe₂TiO₅ heterojunction for solar water splitting. • Higher photocurrent density c.a 1.4 mA/cm² at 1.23V_RHE as compared to pristine oxides. • High surface charge separation efficiency of around 85% at 1.23V_RHE. • Enhanced performance due to efficient surface states mediated hole transfer process. We have constructed a Fe₂O₃/Fe₂TiO₅ heterojunction based photoanode deposited on Fluorine Doped Tin Oxide (FTO) substrate by initially fabricating hematite (Fe₂O₃) nanorods and subsequently pseudobrookite (Fe₂TiO₅) nanoporous thin film on top of them. Comparatively lower annealing temperature of 650 °C (usually 750 °C or above) was used to avoid degradation of FTO. The crystalline Fe₂O₃/Fe₂TiO₅ heterojunction shows a considerable enhancement in photocurrent density ca. 1.4 mA/cm² and high surface charge separation efficiency of 85% at operating voltage of 1.23 V vs RHE as compared to its constituents. The crystalline heterojunction showed overall improvement in performance due to enhanced charge separation owing to the favorable band alignment with Fe₂O₃ nanorods and efficient injection of photogenerated holes through surface states into the electrolyte observed through Electrochemical Impedance Spectroscopy.

[en] Graphical abstract: The noble-metal-free g-C₃N₄/Ni(dmgH)₂ composites show efficient and stable photocatalytic hydrogen evolution under visible light in triethanolamine aqueous solution. - Highlights: • Ni(dmgH)₂ sub-microwires as new noble-metal-free co-catalysts for H₂ evolution reaction. • Ni(dmgH)₂/g-C₃N₄ composites show highly efficient H₂ generation in visible light. • The 1-D feature of Ni(dmgH)₂ promotes charge transfer and electron–hole separation on g-C₃N₄. - Abstract: We report an economic photocatalytic H₂ generation system consisting of earth-abundant elements only by coupling graphitic carbon nitride (g-C₃N₄) with Ni(dmgH)₂ sub-microwires that serve as effective co-catalysts for H₂ evolution. This composite photocatalyst exhibits efficient hydrogen evolution under visible-light irradiation in the presence of triethanolamine as electron donor. The optimal coupling of 3.5 wt% Ni(dmgH)₂ to g-C₃N₄ (5 mg composite) allows for a steady H₂ generation rate of 1.18 μmol/h with excellent stability. This study demonstrates that the combination of polymeric g-C₃N₄ semiconductor and small proportion of transition-metal-based co-catalyst could serve as a stable, earth-abundant and low-cost system for solar-to-hydrogen conversion