Properties of 8^{8}Be and 12^{12}C deduced from the folding--potential model

The $\alpha$--$\alpha$ differential cross sections are analyzed in the optical model using a double--folded potential. With the knowledge of this potential bound and resonance--state properties of $\alpha$--cluster states in $^{8}$Be and $^{12}$C as well as astrophysical S--factors of $^{4}$He($\alpha$,$\gamma$)$^{8}$Be and $^{8}$Be($\alpha$,$\gamma$)$^{12}$C are calculated. $\Gamma_{\gamma}$--widths and B(E2)--values are deduced.Comment: 2 pages LaTeX, 2 figures can be obtained from the author

A missing dimension in measures of vaccination impacts

Immunological protection, acquired from either natural infection or vaccination, varies among hosts, reflecting underlying biological variation and affecting population-level protection. Owing to the nature of resistance mechanisms, distributions of susceptibility and protection entangle with pathogen dose in a way that can be decoupled by adequately representing the dose dimension. Any infectious processes must depend in some fashion on dose, and empirical evidence exists for an effect of exposure dose on the probability of transmission to mumps-vaccinated hosts [1], the case-fatality ratio of measles [2], and the probability of infection and, given infection, of symptoms in cholera [3]. Extreme distributions of vaccine protection have been termed leaky (partially protects all hosts) and all-or-nothing (totally protects a proportion of hosts) [4]. These distributions can be distinguished in vaccine field trials from the time dependence of infections [5]. Frailty mixing models have also been proposed to estimate the distribution of protection from time to event data [6], [7], although the results are not comparable across regions unless there is explicit control for baseline transmission [8]. Distributions of host susceptibility and acquired protection can be estimated from dose-response data generated under controlled experimental conditions [9]–[11] and natural settings [12], [13]. These distributions can guide research on mechanisms of protection, as well as enable model validity across the entire range of transmission intensities. We argue for a shift to a dose-dimension paradigm in infectious disease science and community health

Preconceptual Design Description for Caustic Recycle Facility

The U.S. Department of Energy plans to vitrify both high-level and low-activity waste at the Hanford Site in southeastern Washington State. One aspect of the planning includes a need for a caustic recycle process to separate sodium hydroxide for recycle. Sodium is already a major limitation to the waste-oxide loading in the low-activity waste glass to be vitrified at the Waste Treatment Plant, and additional sodium hydroxide will be added to remove aluminum and to control precipitation in the process equipment. Aluminum is being removed from the high level sludge to reduce the number of high level waste canisters produced. A sodium recycle process would reduce the volume of low-activity waste glass produced and minimize the need to purchase new sodium hydroxide, so there is a renewed interest in investigating sodium recycle. This document describes an electrochemical facility for recycling sodium for the WTP

Feasibility of Knots to Reduce the Maximum Dynamic Arresting Load in Rope Systems

Impact loads to the human body due to falls from height can be mitigated by well-designed and characterized fall protection systems. While energy absorption methods using rope deformation and/or accessory components have previously been evaluated, the ability for simple knots tied in the system to alter impact loads has not been studied in detail. We quantify the effectiveness of various common knots to reduce dynamic loads in typical fall scenarios for which the systems are designed, and interpret this change in the context of rope strength reduction due to the knot. Knots are shown to significantly (45–60 %) reduce the quasistatic strength of rope when compared to a manufactured sewn-eye (40 %). A single exception to this outcome is with the quadruple overhand on a bite (30–35 %). Knots significantly reduce the maximum arresting load due to a dynamic impact event when compared to ropes without knots, providing significantly more energy absorption than the sewn-eye alone. In nearly all rope/knot combinations, the ratio of maximum arrest load (MAL) to breaking strength was lower with the knotted ropes when compared to the sewn-eye terminations. In particular, the quadruple overhand on a bite tied in the Technora–Technora rope resulted in MALs that were only 33 % of the minimum breaking strength (MBS). Ropes with sewn-eye terminations resulted in MALs that were 80 % of the MBS. From the scenarios investigated, the quadruple overhand on a bite provides a favorable reduction in arrest loads with the smallest associated loss of strength.This research was funded by the Department of Homeland Security’s Assistance to Firefighters Grant Program’s Fire Prevention and Safety Grants through Grant # EMW-2008-FP-02504.Ope

Quantum Monte Carlo calculations of A=9,10A=9,10 nuclei

We report on quantum Monte Carlo calculations of the ground and low-lying excited states of $A=9,10$ nuclei using realistic Hamiltonians containing the Argonne $v_{18}$ two-nucleon potential alone or with one of several three-nucleon potentials, including Urbana IX and three of the new Illinois models. The calculations begin with correlated many-body wave functions that have an $\alpha$-like core and multiple p-shell nucleons, $LS$-coupled to the appropriate $(J^{\pi};T)$ quantum numbers for the state of interest. After optimization, these variational trial functions are used as input to a Green's function Monte Carlo calculation of the energy, using a constrained path algorithm. We find that the Hamiltonians that include Illinois three-nucleon potentials reproduce ten states in $^9$Li, $^9$Be, $^{10}$Be, and $^{10}$B with an rms deviation as little as 900 keV. In particular, we obtain the correct 3$^+$ ground state for $^{10}$B, whereas the Argonne $v_{18}$ alone or with Urbana IX predicts a 1$^+$ ground state. In addition, we calculate isovector and isotensor energy differences, electromagnetic moments, and one- and two-body density distributions.Comment: 28 pages, 12 tables, 7 figure

Economic Feasibility of Electrochemical Caustic Recycling at the Hanford Site

This report contains a review of potential cost benefits of NaSICON Ceramic membranes for the separation of sodium from Hanford tank waste. The primary application is for caustic recycle to the Waste Treatment and Immobilization Plant (WTP) pretreatment leaching operation. The report includes a description of the waste, the benefits and costs for a caustic-recycle facility, and Monte Carlo results obtained from a model of these costs and benefits. The use of existing cost information has been limited to publicly available sources. This study is intended to be an initial evaluation of the economic feasibility of a caustic recycle facility based on NaSICON technology. The current pretreatment flowsheet indicates that approximately 6,500 metric tons (MT) of Na will be added to the tank waste, primarily for removing Al from the high-level waste (HLW) sludge (Kirkbride et al. 2007). An assessment (Alexander et al. 2004) of the pretreatment flowsheet, equilibrium chemistry, and laboratory results indicates that the quantity of Na required for sludge leaching will increase by 6,000 to 12,000 MT in order to dissolve sufficient Al from the tank-waste sludge material to maintain the number of HLW canisters produced at 9,400 canisters as defined in the Office of River Protection (ORP) System Plan (Certa 2003). This additional Na will significantly increase the volume of LAW glass and extend the processing time of the Waste Treatment and Immobilization Plant (WTP). Future estimates on sodium requirements for caustic leaching are expected to significantly exceed the 12,000-MT value and approach 40,000-MT of total sodium addition for leaching (Gilbert, 2007). The cost benefit for caustic recycling is assumed to consist of four major contributions: 1) the cost savings realized by not producing additional immobilized low-activity waste (ILAW) glass, 2) caustic recycle capital investment, 3) caustic recycle operating and maintenance costs, and 4) research and technology costs needed to deploy the technology. In estimating costs for each of these components, several parameters are used as inputs. Due to uncertainty in assuming a singular value for each of these parameters, a range of possible values is assumed. A Monte Carlo simulation is then performed where the range of these parameters is exercised, and the resulting range of cost benefits is determined

Alpha scattering and capture reactions in the A = 7 system at low energies

Differential cross sections for $^3$He-$\alpha$ scattering were measured in the energy range up to 3 MeV. These data together with other available experimental results for $^3$He $+ \alpha$ and $^3$H $+ \alpha$ scattering were analyzed in the framework of the optical model using double-folded potentials. The optical potentials obtained were used to calculate the astrophysical S-factors of the capture reactions $^3$He$(\alpha,\gamma)^7$Be and $^3$H$(\alpha,\gamma)^7$Li, and the branching ratios for the transitions into the two final $^7$Be and $^7$Li bound states, respectively. For $^3$He$(\alpha,\gamma)^7$Be excellent agreement between calculated and experimental data is obtained. For $^3$H$(\alpha,\gamma)^7$Li a $S(0)$ value has been found which is a factor of about 1.5 larger than the adopted value. For both capture reactions a similar branching ratio of $R = \sigma(\gamma_1)/\sigma(\gamma_0) \approx 0.43$ has been obtained.Comment: submitted to Phys.Rev.C, 34 pages, figures available from one of the authors, LaTeX with RevTeX, IK-TUW-Preprint 930540

PEP Integrated Test D Run Report Caustic and Oxidative Leaching in UFP-VSL-T02A

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes" of the External Flowsheet Review Team (EFRT) issue response plan. The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario (Test B and D) has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario (Test A) has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP and vessels UFP VSL-00001A and B in the WTP PTF). In Test D, 19M sodium hydroxide (NaOH, caustic) was added to the waste slurry in the UFP VSL T02 vessel after the solids were concentrated to ~20% undissolved solids. The NaOH was added to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by heating to 85°C using direct injection of steam to accelerate the leach process. The main difference of Test D compared to Test B is that the leach temperature is 85°C for 24 hrs as compared to 100°C for 12 hours. The other difference is the Test D simulant had Cr in the simulant from the start of processing and Test B had Cr added to adjust the simulant composition after aluminum leaching. Following the caustic leach, the UFP-VSL-T02A vessel contents are cooled using the vessel cooling jacket. The slurry was then concentrated to 17 wt% undissolved solids and washed with inhibited water to remove NaOH and other soluble salts. Next, the slurry was oxidatively leached using sodium permanganate to solubilize chrome. The slurry was then washed to remove the dissolved chrome and concentrated

PEP Run Report for Simulant Shakedown/Functional Testing

Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Waste Treatment Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, "Undemonstrated Leaching Processes." The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing. Two operating scenarios are currently being evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-2 ultrafiltration feed vessels (i.e., vessel UFP-VSL-T02A in the PEP; and vessels UFP-VSL-00002A and B in the WTP PTF). The second scenario has caustic leaching conducted in the UFP-1 ultrafiltration feed preparation vessels (i.e., vessels UFP-VSL-T01A and B in the PEP; vessels UFP-VSL-00001A and B in the WTP PTF). In both scenarios, 19-M sodium hydroxide solution (NaOH, caustic) is added to the waste slurry in the vessels to leach solid aluminum compounds (e.g., gibbsite, boehmite). Caustic addition is followed by a heating step that uses direct injection of steam to accelerate the leach process. Following the caustic leach, the vessel contents are cooled using vessel cooling jackets and/or external heat exchangers. The main difference between the two scenarios is that for leaching in UFP-1, the 19-M NaOH is added to un-concentrated waste slurry (3-8 wt% solids), while for leaching in UFP-2, the slurry is concentrated to nominally 20 wt% solids using cross-flow ultrafiltration before the addition of caustic. In both scenarios, following the caustic leach, the slurry was then concentrated to 17 wt% and washed with inhibited water to remove NaOH and other soluble salts. Next, the slurry was oxidatively leached using sodium permanganate to solubilize chrome. The slurry was then washed to remove the dissolved chrome and concentrated

Correlations in a Many-Body Calculation of 11^{\bf 11}Li

A many-body calculation of $^{11}$Li is presented where the only input is the well-tested, finite-range {\it D1S} effective interaction of {\it Gogny}. Pairing correlations are included in a constrained Hartree-Fock-Bogolyubov calculation, while long-range collective correlations are introduced using a GCM derived calculation. Correlations are found to play an important role in describing $^{11}$Li. A substantive underlying $^9$Li core of $^{11}$Li is found, which has a different density profile than a free $^9$Li nucleus. This may have significant implications in the use of a three-body framework in studies of $^{11}$Li.Comment: 23 pages typeset in revtex 2.0 with 8 postscript figures in accompanying uuencoded fil