Measurement of species flux from a bubble using an acousto-electrochemical technique

An acousto-electrochemical technique is presented which, for the first time, offers the potential for measuring the flux of dissolved species in a liquid resulting from bubbles of a specific chosen size in the population. Laboratory trials are presented, but the device itself was damaged in the surf zone and no data was obtained from the ocean deployment. Nevertheless, the preceding laboratory tests demonstrate the viability of the technique. The device responds to perturbations of the fluid around a small electrode. Three such sources of motion must be characterised if it is to achieve the objective stated above. First, the perturbations resulting form the translatory motions of bubbles in the liquid. To obtain bubble radius resolution in the measurement of mass flux, however, it is necessary to apply to driving (‘pump’) sound field. Bubbles close to resonance will, in addition to a translatory motion, impart to the liquid a component of mass flux at the pump frequency. This is detected. However to show that this is the result of bubble wall pulsation, and not someother coupling, the amplitude of the pump field is increased until the electrochemical sensor detects Faraday waves on the bubble wall. Not only does this prove the relation between mass flux to bubble wall motion, it provides a second route by which the radius-resolved component of mass flux might be identified. In these preliminary laboratory tests, electrochemical detection of these motions was achieved through the observation of current produced by the reduction of a suitable redox agent present within the liquid phase of the solution employed. Preparations were made to obtain preliminary data from the Hurst Spit 2000 surf zone trial, but the device was damaged by the environment

Study of the Effects on Turbocharger Performance Generated by the Presence of Foreign Objects at the Compressor Intake

The study performed on this work consists of evaluating the consequences of the introduction of various foreign objects at the compressor inlet of a turbocharger. The most plausible objects were selected. A specific test bench was set up in order to perform the experiment and measure the compression ratio and compressor efficiency evolution. Measurements were performed before (healthy compressor) and after the object introduction (damaged compressor). Results obtained indicate that losses in performance can be very important, but also that the compressor can swallow hard objects without visible damage. Therefore the experiments were filmed with a high speed camera. Visual information has helped to better understand the phenomenon, to explain the measurements and it has been taken into account in order to perform final diagnosis. As expected, the harder the object is and the longer it hits compressor wheel before being swallowed, the most severe is the damage. Nevertheless, softer material can reach abnormal performance but in randomly manner and such incipient damage can be detected easily in high air flow rates than in lower.The authors wish to thank Spanish Grant TRA2007-65433/TAIR from Ministerio de Educacion y Ciencia. D.G. Investigacion for supporting this work.Serrano Cruz, JR.; Tormos Martínez, BV.; Gargar, KL.; Bouffaud, F. (2013). Study of the Effects on Turbocharger Performance Generated by the Presence of Foreign Objects at the Compressor Intake. Experimental Techniques. 37(2):30-40. https://doi.org/10.1111/j.1747-1567.2011.00795.xS3040372Watson, N., & Janota, M. S. (1982). Turbocharging the Internal Combustion Engine. doi:10.1007/978-1-349-04024-7Gjika , K. Larue , G.D. “Dynamic Behaviour of Rotor-Bearing Systems Involving Two Oil Films in Series-Application to High-Speed Turbochargers,” IMechE Conference Transactions C602/021/2002. Seventh International Conference on Turbochargers and Turbocharging 2002Galindo, J., Serrano, J. R., Guardiola, C., & Cervelló, C. (2006). Surge limit definition in a specific test bench for the characterization of automotive turbochargers. Experimental Thermal and Fluid Science, 30(5), 449-462. doi:10.1016/j.expthermflusci.2005.06.002Engels , B. “Lifetime Prediction for Turbocharger Compressor Wheels-Why Use Titanium?” IMechE Conference Transactions C602/037/2002. Seventh International Conference on Turbochargers and Turbocharging 2002Ahdad , F. Soare , M.A. “Prediction of Duration of Life of Automotive Components under Thermomechanical Fatigue,” IMechE Conference Transactions C602/020/2002. Seventh International Conference on Turbochargers and Turbocharging 2002Holmes , R. “Turbocharger Vibration - A Case Study,” IMechE Conference Transactions C692/031/2002. Seventh International Conference on Turbochargers and Turbocharging 2002Zhao , X. He , H. Xu , S. “Influence of the Floating-Ring Bearing Parameters on Stability of Turbocharger Rotor-Bearing System,” Proceedings of the Fourth International Symposium of Fluid Machinery and Fluid Engineering. 421 425 2008SAE J1826 Turbocharger Gas Stand Test Code, Recommended Practice 1995Luján , J.M. Bermudez , V. Serrano , J.R. Cervelló , C. “Test Bench for Turbocharger Groups Characterization,” SAE Paper 2002-01-0163.Serrano , J.R. Guardiola , C. Dolz , V. Tiseira , A. Cervelló , C. “Experimental Study of the Turbine Inlet Gas temperature influence on Turbocharger Performance,” SAE Paper 2007-01-1559.Macián, V., Luján, J. M., Bermúdez, V., & Guardiola, C. (2004). Exhaust pressure pulsation observation from turbocharger instantaneous speed measurement. Measurement Science and Technology, 15(6), 1185-1194. doi:10.1088/0957-0233/15/6/020The International Council on Combustion Engines (CIMAC) Turbocharging Efficiencies - Definitions and Guidelines for Measurements and Calculation 200

Modelling spatial and inter-annual variations of nitrous oxide emissions from UK cropland and grasslands using DailyDayCent

This work contributes to the Defra funded projects AC0116: ‘Improving the nitrous oxide inventory’, and AC0114: ‘Data Synthesis, Management and Modelling’. Funding for this work was provided by the UK Department for Environment, Food and Rural Affairs (Defra) AC0116 and AC0114, the Department of Agriculture, Environment and Rural Affairs for Northern Ireland, the Scottish Government and the Welsh Government. Rothamsted Research receives strategic funding from the Biotechnology and Biological Sciences Research Council. This study also contributes to the projects: N-Circle (BB/N013484/1), U-GRASS (NE/M016900/1) and GREENHOUSE (NE/K002589/1).Peer reviewedPublisher PD

Family involvement in eating disorder treatment among Latinas

Latinos are less likely to seek health care for eating disorders and more likely to drop out of treatment than members of other ethnic groups, highlighting existing challenges to engagement in traditional mental health care. This study explored the role of family in the treatment of adult Latinas with eating disorders through content analysis of family sessions adjunctive to cognitive behavioral therapy. This study yielded insight into the experiences of 10 Latinas with eating disorders (M age = 39.90 years) and 10 relatives (M age = 39.50) from the Promoviendo una Alimentación Saludable trial who were randomly selected to receive six family enhancement sessions. Data from 53 sessions were analyzed using a qualitative content analysis approach. Family intervention might serve as a valuable adjunct to conventional treatment by positively influencing social, family, and emotional support for Latinas with eating disorders

Reducing nitrous oxide emissions by changing N fertiliser use from calcium ammonium nitrate (CAN) to urea based formulations

This research was financially supported under the National Development Plan, through the Research Stimulus Fund, administered by the Department of Agriculture, Food and the Marine (Grant numbers RSF10-/RD/SC/716 and RSF11S138) and from the Department of Agriculture and Rural Development (Ref: DARD Evidence and Innovation project 13/04/06) for Northern Ireland. The first author gratefully acknowledges funding received from the Teagasc Walsh Fellowship Scheme (Ref: 2012005).peer-reviewedThe accelerating use of synthetic nitrogen (N) fertilisers, to meet the world's growing food demand, is the primary driver for increased atmospheric concentrations of nitrous oxide (N2O). The IPCC default emission factor (EF) for N2O from soils is 1% of the N applied, irrespective of its form. However, N2O emissions tend to be higher from nitrate-containing fertilisers e.g. calcium ammonium nitrate (CAN) compared to urea, particularly in regions, which have mild, wet climates and high organic matter soils. Urea can be an inefficient N source due to NH3 volatilisation, but nitrogen stabilisers (urease and nitrification inhibitors) can improve its efficacy. This study evaluated the impact of switching fertiliser formulation from calcium ammonium nitrate (CAN) to urea-based products, as a potential mitigation strategy to reduce N2O emissions at six temperate grassland sites on the island of Ireland. The surface applied formulations included CAN, urea and urea with the urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) and/or the nitrification inhibitor dicyandiamide (DCD). Results showed that N2O emissions were significantly affected by fertiliser formulation, soil type and climatic conditions. The direct N2O emission factor (EF) from CAN averaged 1.49% overall sites, but was highly variable, ranging from 0.58% to 3.81. Amending urea with NBPT, to reduce ammonia volatilisation, resulted in an average EF of 0.40% (ranging from 0.21 to 0.69%)-compared to an average EF of 0.25% for urea (ranging from 0.1 to 0.49%), with both fertilisers significantly lower and less variable than CAN. Cumulative N2O emissions from urea amended with both NBPT and DCD were not significantly different from background levels. Switching from CAN to stabilised urea formulations was found to be an effective strategy to reduce N2O emissions, particularly in wet, temperate grassland.Department of Agriculture and Rural Development for Northern IrelandTeagasc Walsh Fellowship ProgrammeDepartment of Agriculture, Food and the Marin

The contribution of cattle urine and dung to nitrous oxide emissions: Quantification of country specific emission factors and implications for national inventories

Publication history: Accepted - 10 April 2018; Published online - 24 April 2018.Urine patches and dung pats from grazing livestock create hotspots for production and emission of the greenhouse gas, nitrous oxide (N2O), and represent a large proportion of total N2O emissions in many national agricultural greenhouse gas inventories. As such, there is much interest in developing country specific N2O emission factors (EFs) for excretal nitrogen (EF3, pasture, range and paddock) deposited during gazing. The aims of this study were to generate separate N2O emissions data for cattle derived urine and dung, to provide an evidence base for the generation of a country specific EF for the UK from this nitrogen source. The experiments were also designed to determine the effects of site and timing of application on emissions, and the efficacy of the nitrification inhibitor, dicyandiamide (DCD) on N2O losses. This co-ordinated set of 15 plot-scale, year-long field experiments using static chambers was conducted at five grassland sites, typical of the soil and climatic zones of grazed grassland in the UK. We show that the average urine and dung N2O EFs were 0.69% and 0.19%, respectively, resulting in a combined excretal N2O EF (EF3), of 0.49%, which is b25% of the IPCC default EF3 for excretal returns from grazing cattle. Regression analysis suggests that urineN2O EFs were controlledmore by composition than was the case for dung, whilst dung N2O EFs were more related to soil and environmental factors. The urine N2O EF was significantly greater from the site in SW England, and significantly greater from the early grazing season urine application than later applications. Dycandiamide reduced the N2O EF fromurine patches by an average of 46%. The significantly lower excretal EF3 than the IPCC default has implications for the UK's national inventory and for subsequent carbon footprinting of UK ruminant livestock productsThe authors are grateful to the UK Department for Environment, Food and Rural Affairs (Defra), the Department of Agriculture and Rural Development (now the Department of Agriculture, Environment and Rural Affairs) in Northern Ireland, and the Scottish Government and the Welsh Government for financial support via the InveN2Ory project (AC0116). The work by Rothamsted Research was additionally supported by the Biotechnology and Biological Sciences Research Council (BBS/E/C/000I0320). We would also like to thank Jon Moorby (IBERS, Wales, UK), Reading University, SRUC (Scotland, UK) and Conrad Ferris (AFBI, Northern Ireland, UK), for provision of cattle urine and dung

Cluster structure of 13C probed via the 7Li(9Be,13C*->9Be+alpha) reaction

A study of the 7Li(9Be,4He9Be)3H reaction at E{beam}=70 MeV has been performed using resonant particle spectroscopy techniques and provides a measurement of alpha-decaying states in 13C. Excited states are observed at 12.0, 13.4, 14.1, 14.6, 15.2, 16.8, 17.9, 18.7, 21.3 and 23.9 MeV. This study provides the first measurement of the three highest energy states. Angular distribution measurements have been performed and have been employed to indicate the transferred angular momentum for the populated states. These data are compared with recent speculations of the presence of chain-like structures in 13C.Comment: accepted for publication in Nuclear Physics

alpha-decay of excited states in 11C and 11B

Studies of the 16O(9Be,alpha7Be)14C and 7Li(9Be,alpha7Li)5He reactions at E{beam}=70 MeV have been performed using resonant particle spectroscopy techniques. The 11C excited states decaying into alpha+7Be(gs) are observed at 8.65, 9.85, 10.7 and 12.1 MeV as well as possible states at 12.6 and 13.4 MeV. This result is the first observation of alpha-decay for excited states above 9 MeV. The alpha+7Li(gs) decay of 11B excited states at 9.2, 10.3, 10.55, 11.2, (11.4), 11.8, 12.5,(13.0), 13.1, (14.0), 14.35, (17.4) and (18.6) MeV is observed. The decay processes are used to indicate the possible three-centre 2alpha+3He(3H) cluster structure of observed states. Two rotational bands corresponding to very deformed structures are suggested for the positive-parity states. Excitations of some observed T=1/2 resonances coincide with the energies of T=3/2 states which are the isobaric analogs of the lowest 11Be states. Some of these states may have mixed isospin.Comment: accepted for publication in Nuclear Physics

Plasma Wakefield Acceleration with a Modulated Proton Bunch

The plasma wakefield amplitudes which could be achieved via the modulation of a long proton bunch are investigated. We find that in the limit of long bunches compared to the plasma wavelength, the strength of the accelerating fields is directly proportional to the number of particles in the drive bunch and inversely proportional to the square of the transverse bunch size. The scaling laws were tested and verified in detailed simulations using parameters of existing proton accelerators, and large electric fields were achieved, reaching 1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found in this case.Comment: 9 pages, 7 figure

The energy dependence of ptp_t angular correlations inferred from mean-ptp_{t} fluctuation scale dependence in heavy ion collisions at the SPS and RHIC

We present the first study of the energy dependence of $p_t$ angular correlations inferred from event-wise mean transverse momentum fluctuations in heavy ion collisions. We compare our large-acceptance measurements at CM energies $\sqrt{s_{NN}} =$ 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. $p_t$ angular correlation structure suggests that the principal source of $p_t$ correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with $\ln \sqrt{s_{NN}}$ from the onset of observable jet-related fluctuations near 10 GeV.Comment: 10 pages, 4 figure