Big Bang Nucleosynthesis with Gaussian Inhomogeneous Neutrino Degeneracy

We consider the effect of inhomogeneous neutrino degeneracy on Big Bang nucleosynthesis for the case where the distribution of neutrino chemical potentials is given by a Gaussian. The chemical potential fluctuations are taken to be isocurvature, so that only inhomogeneities in the electron chemical potential are relevant. Then the final element abundances are a function only of the baryon-photon ratio $\eta$, the effective number of additional neutrinos $\Delta N_\nu$, the mean electron neutrino degeneracy parameter $\bar \xi$, and the rms fluctuation of the degeneracy parameter, $\sigma_\xi$. We find that for fixed $\eta$, $\Delta N_\nu$, and $\bar \xi$, the abundances of helium-4, deuterium, and lithium-7 are, in general, increasing functions of $\sigma_\xi$. Hence, the effect of adding a Gaussian distribution for the electron neutrino degeneracy parameter is to decrease the allowed range for $\eta$. We show that this result can be generalized to a wide variety of distributions for $\xi$.Comment: 9 pages, 3 figures, added discussion of neutrino oscillations, altered presentation of figure

Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative

An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development and implementation of the SEI nuclear propulsion safety program. In addition, the NSPWG has reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. These recommendations should be useful for the development of the program's top-level requirements for safety functions (referred to as Safety Functional Requirements). The safety requirements and guidelines address the following topics: reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations

Proliferation Resistance and Physical Protection Evaluation Methodology Development and Applications

An overview of the technical progress and accomplishments on the evaluation methodology for proliferation resistance and physical protection of Generation IV nuclear energy Systems

Overview of the Facility Safeguardability Analysis (FSA) Process

The safeguards system of the International Atomic Energy Agency (IAEA) provides the international community with credible assurance that a State is fulfilling its nonproliferation obligations. The IAEA draws such conclusions from the evaluation of all available information. Effective and cost-efficient IAEA safeguards at the facility level are, and will remain, an important element of this “State-level” approach. Efficiently used, the Safeguards by Design (SBD) methodologies , , , now being developed can contribute to effective and cost-efficient facility-level safeguards. The Facility Safeguardability Assessment (FSA) introduced here supports SBD in three areas. 1. It describes necessary interactions between the IAEA, the State regulator, and the owner / designer of a new or modified facility to determine where SBD efforts can be productively applied, 2. It presents a screening approach intended to identify potential safeguard issues for; a) design changes to existing facilities; b) new facilities similar to existing facilities with approved safeguards approaches, and c) new designs, 3. It identifies resources (the FSA toolkit), such as good practice guides, design guidance, and safeguardability evaluation methods that can be used by the owner/designer to develop solutions for potential safeguards issues during the interactions with the State regulator and IAEA. FSA presents a structured framework for the application of the SBD tools developed in other efforts. The more a design evolves, the greater the probability that new safeguards issues could be introduced. Likewise, for first-of-a-kind facilities or research facilities that involve previously unused processes or technologies, it is reasonable to expect that a number of possible safeguards issues might exist. Accordingly, FSA is intended to help the designer and its safeguards experts identify early in the design process: • Areas where elements of previous accepted safeguards approach(es) may be applied to facility modifications or new designs • Modifications of the design that could mitigate a potential safeguards issue or facilitate a more efficient application of the safeguards approach • Possible innovative ideas for more efficient application of safeguards • The potential for changes in elements of the safeguard approach that may be required by IAEA as a result of facility design features and characteristics • Other potential concerns These issues will then be presented to the IAEA and the state regulator to be resolved in a timely manner, ensuring that the planned safeguards approach is acceptable and compatible with the facility design. The proposed approach should be validated by application to suitable facilities to assess its utility, comprehensiveness, and cost-effectiveness. The approach and example application should also be reviewed by industry to confirm the conclusions reached in the DOE review

Cosmological parameters from SDSS and WMAP

We measure cosmological parameters using the three-dimensional power spectrum P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in combination with WMAP and other data. Our results are consistent with a ``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt, tensor modes or massive neutrinos. Adding SDSS information more than halves the WMAP-only error bars on some parameters, tightening 1 sigma constraints on the Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when dropping prior assumptions about curvature, neutrinos, tensor modes and the equation of state. Our results are in substantial agreement with the joint analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive consistency check with independent redshift survey data and analysis techniques. In this paper, we place particular emphasis on clarifying the physical origin of the constraints, i.e., what we do and do not know when using different data sets and prior assumptions. For instance, dropping the assumption that space is perfectly flat, the WMAP-only constraint on the measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running tilt, neutrino mass and equation of state in the list of free parameters, many constraints are still quite weak, but future cosmological measurements from SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt figures available at http://www.hep.upenn.edu/~max/sdsspars.htm

Characterizing the multi-dimensional reaction dynamics of dihalomethanes using XUV-induced Coulomb explosion imaging

Site-selective probing of iodine 4d orbitals at 13.1 nm was used to characterize the photolysis of CH2I2 and CH2BrI initiated at 202.5 nm. Time-dependent fragment ion momenta were recorded using Coulomb explosion imaging mass spectrometry and used to determine the structural dynamics of the dissociating molecules. Correlations between these fragment momenta, as well as the onset times of electron transfer reactions between them, indicate that each molecule can undergo neutral three-body photolysis. For CH2I2, the structural evolution of the neutral molecule was simultaneously characterized along the C-I and I-C-I coordinates, demonstrating the sensitivity of these measurements to nuclear motion along multiple degrees of freedom

Distributed hydrological modelling for forecasting water discharges from the land area draining to the Great Barrier Reef coastline

The physical-conceptual distributed hydrological model Grid-to-Grid, or G2G, is applied across the 426, 000 km2 land area draining to the Great Barrier Reef (GBR) coastline of Queensland, Australia. Of this area, 76, 600 km2 is ungauged, this being the land between the most downstream gauging locations and the coastline. G2G provides gridded hourly river flows across the model domain, of use for both flood and water availability forecasting in Queensland, as well as hourly coastal discharges required by marine models of the Reef environment employed for conservation purposes. G2G is underpinned by spatial datasets on terrain, land-cover and soil properties. The best sources for these datasets have been identified and developed to support generic application of G2G across Australia. These include the Australian Digital Elevation Model and Digital Atlas of Australian Soils and serve to shape the hydrological response to rainfall patterns in time and space. Raingauge observations along with the AustralianWater Availability Project (AWAP) gridded rainfall are used to generate 1 km gridded historical rainfall. The ACCESS-R numerical weather prediction model is used to generate 1 km gridded forecast rainfall over a lead-time of three days. The model’s area-wide formulation allows for the production of real-time flow forecasts everywhere on a 1km grid across the model domain, including those areas which are ungauged. G2G is calibrated over the GBR land area, and the modelling capability assessed through comparison with gauged river flow records at 276 locations over a nine year period. A novel method, employing data assimilation of the furthest downstream gauged river flows, is used to obtain improved coastal discharge estimates required by the marine models. The G2G historical simulations and nowcasts are linked to statistical water quality models to generate sediment, nitrogen and phosphorus loads for use in biogeochemistry models, and are being used in generating GBR Annual Report Cards by the Australian Government. Currently, the G2G modelling system to generate long-term historical simulations, nowcasts and forecasts is not operational but work is in progress to make the system operational in the near future. The work is a collaboration between the Bureau of Meteorology Australia and the Centre for Ecology & Hydrology in the UK, and forms part of the eReefs Programme in support of the Reef 2050 Plan

Evaluation of a Cluster-Randomized Controlled Trial of a Package of Community-Based Maternal and Newborn Interventions in Mirzapur, Bangladesh

To evaluate a delivery strategy for newborn interventions in rural Bangladesh.A cluster-randomized controlled trial was conducted in Mirzapur, Bangladesh. Twelve unions were randomized to intervention or comparison arm. All women of reproductive age were eligible to participate. In the intervention arm, community health workers identified pregnant women; made two antenatal home visits to promote birth and newborn care preparedness; made four postnatal home visits to negotiate preventive care practices and to assess newborns for illness; and referred sick neonates to a hospital and facilitated compliance. Primary outcome measures were antenatal and immediate newborn care behaviours, knowledge of danger signs, care seeking for neonatal complications, and neonatal mortality.A total of 4616 and 5241 live births were recorded from 9987 and 11153 participants in the intervention and comparison arm, respectively. High coverage of antenatal (91% visited twice) and postnatal (69% visited on days 0 or 1) home visitations was achieved. Indicators of care practices and knowledge of maternal and neonatal danger signs improved. Adjusted mortality hazard ratio in the intervention arm, compared to the comparison arm, was 1.02 (95% CI: 0.80-1.30) at baseline and 0.87 (95% CI: 0.68-1.12) at endline. Primary causes of death were birth asphyxia (49%) and prematurity (26%). No adverse events associated with interventions were reported.Lack of evidence for mortality impact despite high program coverage and quality assurance of implementation, and improvements in targeted newborn care practices suggests the intervention did not adequately address risk factors for mortality. The level and cause-structure of neonatal mortality in the local population must be considered in developing interventions. Programs must ensure skilled care during childbirth, including management of birth asphyxia and prematurity, and curative postnatal care during the first two days of life, in addition to essential newborn care and infection prevention and management.Clinicaltrials.gov NCT00198627

Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV

The results from the STAR Collaboration on directed flow (v_1), elliptic flow (v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and compared with results from other experiments and theoretical models. Results for identified particles are presented and fit with a Blast Wave model. Different anisotropic flow analysis methods are compared and nonflow effects are extracted from the data. For v_2, scaling with the number of constituent quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures modified, but data the same. However, in Fig. 35 the hydro calculations are corrected in this version. The data tables are available at http://www.star.bnl.gov/central/publications/ by searching for "flow" and then this pape