Lead and nickel distribution in the Cup-PbO-SiO2 and the Cup-NiO-SiO2 Systems equilibrated with liquid copper

The distribution of lead and of nickel between molten copper and a ternary cuprous oxide-metal oxide-silica saturated slag was measured at 1498 K. The results are correlated using ion fractions, calculated either according to Temkin’s method, or as electrically equivalent ion fractions. The simpler method suggested by Temkin correlates slightly better than the other giving the following relations between the ionic concentration quotients and impurity concentration in the metal: logN _Pb ⁺⁺/N ² _Cu ⁺ = logX _Pb + 2.40 ± 0.05, valid up toX _Pb = 0.003 logN _Ni ⁺⁺/N ² _Cu ⁺ = 0.44 logX _Pb + 0.15 ± 0.07, valid up toX _Ni = 0.004. In the nickel systems, an Ni rich phase, identified as NiO, separates from the metal at X_Ni = 0.04 (0.4 wt pct). A tentative phase diagram of the Cu₂O-NiO-SiO₂ system at 1498 K is presented. The data found in this investigation explain why the impurities Pb or Ni cannot be practically reduced to low levels by oxidation. This results from the large amounts of copper that are oxidized in going to low impurity levels. Use of a two-slag refining process is shown to cut slag losses of copper to less than half those encountered with a single slag operation.     

The influence of reserpine on the responsiveness to norepinephrine and electrolyte contents of rabbit atria

This study was designed to investigate the relationships between reserpine-induced supersensitivity and electrolyte levels in isolated rabbit atria. Atria from reserpine-treated (1, 3 or 4 mg/kg 24 hr before) and untreated rabbits were placed in an isolated organ bath for determination of dose-response relationships for norepinephrine, or were used for electrolyte assay. Reserpine-treated atria had greater resting and maximum rates of beat than did untreated atria. However, the ED50 concentrations of norepinephrine producing a rate response were similar. Atria pretreated with 1 or 3 mg/kg reserpine were supersensitive to the inotropic effect of norepinephrine. 4 mg/kg reserpine did not induce inotropic supersensitivity. Atrial sodium contents were significantly increased by 3 mg/kg reserpine. Potassium contents were increased by 1 and 4 mg/kg reserpine. Calcium contents were significantly decreased by 4 mg/kg reserpine, while magnesium contents were increased by 1 and 4 mg/kg. Reserpine induced supersensitivity to the inotropic effects of norepinephrine but did not alter the sensitivity to the chronotropic effect of the drug. This supersensitivity may be linked to alterations in the tissue's homeostatic mechanisms for calcium.     

Integrated sensing and processing decision trees

We introduce a methodology for adaptive sequential sensing and processing in a classification setting. Our objective for sensor optimization is the back-end performance metric--in this case, misclassification rate. Our methodology, which we dub Integrated Sensing and Processing Decision Trees (ISPDT), optimizes adaptive sequential sensing for scenarios in which sensor and/or throughput constraints dictate that only a small subset of all measurable attributes can be measured at any one time. Our decision trees optimize misclassification rate by invoking a local dimensionality reduction-based partitioning metric in the early stages, focusing on classification only in the leaves of the tree. We present the ISPDT methodology and illustrative theoretical, simulation, and experimental results.     

Experimental Study of Ice Jam Formation Dynamics

Ice jams pose a significant threat to human safety and property and represent one of the most dynamic of river ice processes. A key limitation in the advancement of knowledge of ice jam formation is the lack of quantitative data describing these dynamics, which is essential also for validation of advanced computational models. In this study, an experimental investigation of ice jam formation under steady carrier discharge was undertaken. Thus, unsteady effects were entirely due to the ice jam formation process itself. Quantitative data describing the variation in discharge, ice jam thickness, water level variation, and ice cover progression provides unprecedented data describing the dynamics of ice jam formation. While the processes of ice jam formation are indeed dynamic, the results of this investigation suggest that the analysis of ice jams formed under steady carrier flow conditions may be adequately handled by the usual steady flow ice jam stability relationships. The applicability of the popularly applied wide jam theory approach to modeling ice jams is further supported by this investigation.     

Novel Hybrid Filter for the Treatment of Septic Tank Effluent

Intermittent sand filtration is a common and effective method for treating septic tank effluent. However, if the loading rate is too high, clogging and ponding of the sand filter surface layer can occur due to the accumulation of excessive biomass and the deposition of suspended solids. This ponding limits the practicality of sand filtration as it makes it necessary to take the filter out of service for maintenance. The objective of this study was to develop and test, on-site, a new hybrid filter system that would reduce the risk of clogging at an organic loading rate substantially greater than the maximum recommended loading rate for intermittent sand filters. The system comprised a 0.6?m deep horizontal flow biofilm reactor (HFBR) over a 0.85?m deep stratified sand filter. The HFBR consisted of a stack of 20 horizontal corrugated polyvinyl chloride sheets, at 32?mm vertical spacings. The sheets were arranged so that the wastewater flowed over and back along alternate sheets down through the stack. The main biofilm growth formed on these sheets. The hybrid filter was loaded with septic tank effluent from an office/garage complex at the rate of 206?L/m2?day for a period of 400 days in two phases. During the first phase, the effluent volume of 600?L/day was applied in 24 doses/day for 10?min/dose, and during the second phase in 6 doses/day for 40?min/dose. Biofilms in the HFBR substantially reduced the organic and suspended solids loads that reached the sand filter surface and allowed an average total biochemical oxygen demand (BODT) loading rate, based on HFBR plan area, of 37?g?BODT/m2?day to be applied to the system without clogging. This rate was substantially greater than the maximum recommended loading rate of 24?g?BODT/m2?day for intermittent sand filters. During both loading phases a BODT removal of 94% was achieved and nitrification was nearly complete. The average effluent BODT was 12±4?mg/L during both phases. The hybrid filter system appeared to perform better in terms of suspended solids handling and nitrification during the more frequent dosing phase. The hybrid filtration system offers a more compact alternative to intermittent sand filtration on its own with little risk of clogging.     

Effect of Carbonyl Sulphide (COS), Ethyl Formate (EF) and Carbon Disulphide (CS2) on the Malting Quality of Barley and the Flavour Profile of Beer

New fumigants are needed to control grain insects because methyl bromide is being phased out as an ozone‐depleting substance under the Montreal Protocol and because resistance to phosphine is increasing. Alternative fumigants also provide one strategy to manage resistance. To assess the effect of candidate fumigants on barley quality, malting and brewing trials were conducted with malting barley (Schooner), 9.4% moisture content, fumigated with carbonyl sulphide (COS), ethyl formate (EF) and carbon disulphide (CS₂) at concentrations of 20, 90 and 36 mg/L respectively for 7 days at 20°C in riveted steel silos containing 33 t of barley. The appropriate industry body, the Malting and Brewing Industry Barley Technical Committee (MBIBTC) set the quality parameters to be evaluated and allocated work to the appropriate quality laboratories. Germination of fumigated barley was not affected by the fumigants. Residues of COS, EF and CS₂ in outloading barley samples were 0.085 ± 0.0052, 0.4 ± 0.1 and 2.22 ± 0.07 mg/kg respectively, which were below the experimental permits of maximum residue levels (MRL). Residues of COS, EF and CS₂ in malt, wort and beer were indistinguishable from those in unfumigated (or non‐fumigated) barley. Ethyl formate and CS₂ affected wort in increasing the apparent attenuation limit (AAL) and CS₂ affected barley colour. Sulphur volatiles in the trial beer made from EF and CS₂ (unlike COS) fumigated barley decreased significantly. Beer from COS, EF and CS₂ fumigated barley had a somewhat higher 24‐hour chill haze level (0.62–0.84) than beer from the untreated barley (0.53). The total alcohols and isoamyl acetate increased in beer made from EF fumigated barley. Carbonyl sulphide, EF and CS₂, however, had no effect on beer flavour or quality.     

Electrically conducting particle networks in polymer electrolyte as three-dimensional electrodes for hydrogenase electrocatalysis

Efficient H₂ oxidation and production by hydrogenase enzymes has attracted much interest because of the possibilities it raises for clean energy cycling without the need for precious metal catalysts. Although hydrogenases are extremely active electrocatalysts, high surface-area electrode structures will be necessary if the enzymes are to find application in energy technologies. Taking inspiration from fuel cell electrode assemblies, in which metal nanoparticles are commonly mounted on particulate carbon supports encased in polymer electrolyte, we show that high surface-area hydrogenase electrodes can be constructed from enzyme-loaded pyrolytic graphite particles in pH-neutralised Nafion. Pyrolytic graphite is the favoured surface for direct electrochemistry of many redox proteins, and on sanding, yields micron-dimension platelike particles. By modifying graphite platelets with hydrogenase before assembling the particles into a network, we ensure a high, uniform enzyme coverage. Incorporation of hydrogenases into high surface-area conducting network electrodes enhanced electrocatalytic H₂ oxidation currents by 30-times compared to values obtained for a planar hydrogenase electrode, while retaining efficient conductivity and H₂ mass transport through the network. This approach should make it possible to directly compare enzyme and precious metal electrocatalysis and to benchmark what opportunities are possible with selective enzyme catalysts.     

Digital computation of the complex linear canonical transform

An efficient algorithm for the accurate computation of the linear canonical transform with complex transform parameters and with complex output variable is presented. Sampling issues are discussed and the requirements for different cases given. Simulations are provided to validate the results.     

ASME Section Ⅲ Stress Analysis of a Heat Exchanger Tubesheet with a Misdrilled Hole and Irregular or Thin Ligaments

A stress analysis is described for a nuclear steam generator tubesheet with a thin, or irregular ligament, associated with a mis-drilled hole using the rules of ASME （American Society of Mechanical Engineers） B ＆ PV Section Ⅲ and non-mandatory Appendix A, Article A-8000 for stresses in perforated flat plates. The analysis demonstrates the proper application of the NB-3200 rules for this special application, with discussion of the differences between an actual tube hole deviation and what is assumed in ASME Appendix A. This is a companion paper to ＂Technical Justification Supporting Operation with a Tube Installed in a Mis-Drilled Hole of a Steam Generator Tubesheet＂.