CHEMICAL TECHNOLOGY DIVISION, UNIT OPERATIONS SECTION MONTHLY PROGRESS REPORT FOR APRIL 1959

A concentration cell electrode was installed in a fritted glass surface and was used to measure the surface KCl concentration while water was being transpired through the surface into a mixed tank of 0.1 M KCl. The results from the first Fluorox run made with crude UF/sub 4/ showed that 85.3% of the theoretical amount of UF/sub 6/ was accounted for, with 17.9% being collected in cold traps and the remainder being consumed in various side reactions. Installation was completed of apparatus to study the electrolytic removal of nickel on an engineering scale from concentrated HRT fuel solution. An extremely low yield stress of 0.02 lb/sq ft was measured for a thoria-urania slurry containing 2.5 wt.% Al/sub 2/O/sub 3/ and spherical particles of 1.7 micron mean diameter. Preliminary data on the rate of uranium sorption on Dowex 21K from sulfate solutions were correlated with a simple spherical diffusion model. Laboratory scale studies to determine the effect of reflux time, HNO/sub 3/ concentration, and air sparge on chloride removal from APPR-type Darex dissolver product showed that an air sparge is definitely beneficial in chloride removal. Preliminary cyclic cleaning tests showed that boiling 25% caustic solution was adequate for cleaning type F (20 micron) porous metal filter elements fouled in the absence of filter aid with siliceous sludge from Darex solvent extraction feed solutions. Sections of unirradiated stainless steel-clad UO/sub 2/, sheared into lengths of 1/2 in., 1 in., 2 in., and 2 3/4 in., were leached free of UO/sub 2/ with 10 M HNO/sub 3/ in 30, 45, 60, and 75 min, respectively. The abrasive blade cost for the removal of inert end adapters from selected reactor assemblies ranges from 12 for the Gas-Cooled Reactor to 19 for Consolidated Edison. A zirconium dissolution was carried to completion at 600 ction prod- C in a NaF-LiF salt mixture containing initially 23 mol per cent ZrF/sub 4/ at an average rate of 1.3 mg/(cm/sup 2/)(min) with an HF feed rate of 2 lb/hr. The thermal conductivity and thermal diffusivity at the center of an 8-in. diameter cake of Darex waste calcined at about 900 ction prod- C were determined as a function of temperature. (For preceding period see CF-59-3-61.) (auth

CHEMICAL TECHNOLOGY DIVISION, UNIT OPERATIONS SECTION MONTHLY PROGRESS REPORT FOR AUGUST 1959

The measured diffusivity of uranyl nitrate in water at 25 ction prod- C was 0.7 x 10/sup -6/ cm/sup 2//sec with about 40% average deviation. A program was started to develop nonnuclear uses for depleted uranium. Two continuous DRUHM reaction runs were terminated due to erratic operation of the sodium metering system. In the second Fluorox run with crude UF/sub 4/ which lasted for 29 hr, a total material balance of 94.8% was obtained and 17.9% of the theoretical amount of UF/sub 6/ was collected in cold traps and chemical traps. Room temperature flow rate-pressure drop calibrations of a multiclone (thirteen 0.60-in. diam hydroclones in parallel) for installation with the HRT replacement circulating pump were completed. Mixed oxides of U : Th = 0.08 : 1 and all have low yield stresses of 0.02 to 0.05 lb/sq ft compared to 0.2 to 1.0 lb/sq ft for normal Th-U or Th oxides of 1.5 to 2.5 micron mean diameter. The rates of uranium anion exchange from solutions containing between 0.025 and 0.20 M sulfate were measured and apparent uranium diffusion coefficients between 1.2 x 10/sup -7/ cm/sup 2//sec and 1.6 x 10/sup -7/ cm/sup 2//sec were calculated. In bench scale studies, the Darex reference flowsheet was successfully applied to stainless steel-clad UO/sub 2/ fuels (Yankee Atomic) and to aluminumuranium foreign reactor fuels. The corrosion of titanium A-55 was measured in the vapor and liquid phases of a modified boiling Thorex dissolvent (13 M HNO/sub 3/, 0.04 M F/sup -/, 0.1 M H/sub 3/BO/sub 3/) containing 0.0, 0.5, and 1.0 M thorium from dissolved Consolidated Edison pellets and the maximum corrosion rate was 0.6 mils/ month. Siliceous filter cakes resulting from the filtration of Darex solvent extraction feed solutions through porous metal filter elements were easily washed to a uranium loss of 0.1% in the discarded cake. A run with an acid-deficient Darex-Redox feed containing soluble silica resulted in uranium losses higher by a factor of 20 than those previously obtained in the same column with a standard Redox feed. Batch leaching of sheared pieces, 1/2 in. to 5 in. long, of PWR reject UO/sub 2/ pellets clad with stainless steel, 0.40 in. o.d. with 0.10 in. wall, in boiling 10 M HNO/sub 3/ (173% excess) was completed in 70 to 245 min. Dissolution test runs of Zr-2 in fused salt made at approximately 700 ction prod- C under identical conditions except for HF feed rate resulted in dissolution rates of 1.87 and 2.68 mg/min-sq cm for 2.5 and 6.0 lb/hr HF feed rate, respectively. Purex and TBP-25 evaporated wastes were calcined at 900 to 1000 ction prod- C resulting in solid wastes which had densities of 0.77 to 0.83 and 0.40 to 0.45 g/cc, respectively. (For preceding period see CF-59-4-47.) (auth

Chemical Technology Division, Unit Operations Section Monthly Progress Report for June 1959

The addition of a surface active agent to an aqueousorganic interface produced a resistance to mass transfer equivalent to slightly more than 1 cm of water. Five semicontinuous Druhm runs were made with 1/2-in. thick MgO liners and terminated due to either failures of the UF/sub 6/ nozzle or a top gasket leak. In preliminary scale-up tests of the flame calcination equipment, a maximum feed rate equivalent to 720 g oxides/hr was achieved using a 3-in. i.d. magnesia reflector with an outside wall temperature of 1500 ction prod- C. In a test with a light water feed, 99% Cu, 25% Ni, and 0% Mn were removed from a UO/ sub 2/SO/sub 4/ solution by electrolysis with a mercury cathode in 7800 ampere hours. The effect of varying the total sulfate concentration on the kinetics of the absorption of uranyl sulfate on Dowex 21K at a uranium concentration of 0.005779 M and a sulfuric acid concentration of 0.020 M was studied in a series of runs using a stirred bath containing enriched uranium. Chloride was removed to 64 ppm in Yankee Atomic and to 70 ppm in APPR solvent extraction feeds using a reference Darex flowsheet with air sparging during a two hour reflux period in the 10-in. prototype titanium feed adjustment tank. Soluble uranium contained in a filter cake deposited onto a 20 micron porous metallic star shaped filter from approximately twenty-one liters of Darex solvent extraction feed solution was recovered to 99.9% by a single 5 liter water wash of the cake. An experimental Redox solvent extraction program was completed. Shear blade evaluation tests have begun at Birdsboro and Clearing under subcontract and will be completed by July 1. Tests were made on the separation of water associated with sheared material through porous bottom baskets as would be required in wet shearing concepts. Consolidated Edison prototype elements assembled with ductile Coast Metals 50 brazing metal could not be disassembled with the impact wedge previously successfully used to disassemble elements made up with brittle Nicrobraze 50. A reactor and condenser system designed to sublime ZrF/sub 4/ from the hydrofluorinator to a separate receiver at temperatures above 902 ction prod- C was operated at condensation rates between 150 and 500 g per hour of ZrF/sub 4/. The thermal conductivities of granular Darex, Purex, and TBP-25 calcined solids were in the range of 0.043 to 0.097 Btu/hr sq ft ( ction prod- F/ft) at room temperature. (For preceding period see CF-59-5-47.) (auth

CHEMICAL TECHINOLOGY DIVISION, UNIT OPERATIONS SECTION MONTHLY PROGRESS REPORT, APRIL 1960

A critical review of the literature revealed no experiments on uranyl ion transfer from an aqueous to a tributyl phosphate phase which positively measured the kinetics of the chemical reaction at the interphase. Drawing isorhythmic lines on a three component diagram gives a complex correlation for the compaction of three sizes of glass beads. Neither the use of thoria sols nor high feed solution concentrations of thorium nitrate gave any significant increase in mean particle diameters over those obtained from nitrate solutions of lower concentrations in flame denitration. A hydraulic film resistance has been detected in the anion exchange of uranyl sulfate into Dowex 2lK, and chloride elution was found to give a higher apparent uranium diffusion coefficient than nitrate elution. The rate of dissolution of mixed thorium-uranium oxides was determined as a function of the per cent of mixed oxides dissolved. Mixing in tanks packed with boron glass Raschig rings is being continued. The SRE hydraulic dejacketer has been operated successfully with prototype fuel rods. Excessive foaming was encountered when sheared stainless-clad UO/sub 2/ was suddenly contacted with boiling 13 M nitric acid. While attempting to shear a prototype Yankee subassembly with Kanigan brazed diffusion bonded joints, a five tube aggregate was formed at one of the two ferrule locations sheared. Of the 91 protective coatings exposed to ionizing radiation from the HRE, 25 of the coatings outside of the shield and 10 coatings inside the shield exhibited satisfactory resistance. HETS values in the acid Thorex flowsheet are reported. Waste calcination of simulated Purex waste in a 7-in.-diameter vessel gave rates slightly higher than predicted by the radial deposition model because of loss of feed due to excess foaming. (For preceding period see CF-60-6-11.) (auth

Differential effects of pre and post-payment on neurologists' response rates to a postal survey

<p>Abstract</p> <p>Background</p> <p>Monetary incentives are an effective way of increasing response rates to surveys, though they are generally less effective in physicians, and are more effective when the incentive is paid up-front rather than when made conditional on completion.</p> <p>Methods</p> <p>In this study we examine the effectiveness of pre- and post-completion incentives on the response rates of all the neurologists in the UK to a survey about conversion disorder, using a cluster randomised controlled design. A postal survey was sent to all practicing consultant neurologists, in two rounds, including either a book token, the promise of a book token, or nothing at all.</p> <p>Results</p> <p>Three hundred and fifty-one of 591 eligible neurologists completed the survey, for a response rate of 59%. While the post-completion incentive exerted no discernible influence on response rates, a pre-completion incentive did, with an odds-ratio of 2.1 (95% confidence interval 1.5 - 3.0).</p> <p>Conclusions</p> <p>We conclude that neurologists, in the UK at least, may be influenced to respond to a postal survey by a pre-payment incentive but are unaffected by a promised reward.</p

Delivery of antimicrobial stewardship competencies in UK pre-registration nurse education programmes: a national cross-sectional survey

Background: Registered nurses perform numerous functions critical to the success of antimicrobial stewardship but only 63% of pre-registration nursing programmes include any teaching about stewardship. Updated nursing standards highlight nurses require antimicrobial stewardship knowledge and skills. Aim: To explore the delivery of key antimicrobial stewardship competencies within updated pre-registration nursing programmes. Method: A cross-sectional survey design. Data was collected between March and June 2021. Findings: Lecturers from 35 universities responsible for teaching antimicrobial stewardship participated. The provision of antimicrobial stewardship teaching and learning was inconsistent across programmes with competencies in infection prevention and control, patient centred care, and interprofessional collaborative practice taking precedent over those pertaining to the use, management, and monitoring of antimicrobials. On-line learning and teaching surrounding hand hygiene, personal protective equipment, and immunisation theory was reported to have increased during the pandemic. Only a small number of respondents reported that students shared taught learning with other healthcare professional groups. Conclusion: There is a need to ensure consistency in antimicrobial stewardship across programmes, and greater knowledge pertaining to the use, management and monitoring of antimicrobials should be included. Programmes need to adopt teaching strategies and methods that allow nurses to develop interprofessional skill in order to practice collaboratively

Genetics of the Hippocampal Transcriptome in Mouse: A Systematic Survey and Online Neurogenomics Resource

Differences in gene expression in the CNS influence behavior and disease susceptibility. To systematically explore the role of normal variation in expression on hippocampal structure and function, we generated an online microarray database for a diverse panel of strains of mice, including most common inbred strains and numerous recombinant inbred lines (www.genenetwork.org). Using this resource, coexpression networks for families of genes can be generated rapidly to test causal models related to function. The data set is optimized for quantitative trait locus (QTL) mapping and was used to identify over 5500 QTLs that modulate mRNA levels. We describe a wide variety of analyses and novel synthetic approaches that take advantage of this resource, and demonstrate how both the data and associated tools can be applied to the study of gene regulation in the hippocampus and relations to structure and function

Arctic quaternary ostracods and their use in paleoreconstructions

The paper deals with original and published data on fossil ostracodal assemblages from the Eurasian Arctic Kara, Laptev and Chuckchi seas. As a whole, six ecologically different assemblages were distinguished (freshwater, brackish water, marine of the inner, middle and outer shelves and upper continental slope), they replace each other upcore reflecting a gradual increase in water depth and distance from the coast. These assemblages are stable in the entire Arctic region and can be used for interpretation of environments in different Arctic areas