The OPERA trial : a protocol for the process evaluation of a randomised trial of an exercise intervention for older people in residential and nursing accommodation

Background: The OPERA trial is large cluster randomised trial testing a physical activity intervention to address depression amongst people living in nursing and residential homes for older people. A process evaluation was commissioned alongside the trial and we report the protocol for this process evaluation. Challenges included the cognitive and physical ability of the participants, the need to respect the privacy of all home residents, including study non-participants, and the physical structure of the homes. Evaluation activity had to be organised around the structured timetable of homes, leaving limited opportunities for data collection. The aims of this process evaluation are to provide findings that will assist in the interpretation of the clinical trial results, and to inform potential implementation of the physical activity intervention on a wider scale. Methods/design: Quantitative data on recruitment of homes and individuals is being collected. For homes in the intervention arm, data on dose and fidelity of the intervention delivered; including individual rates of participation in exercise classes are collected. In the control homes, uptake and delivery of depression awareness training is monitored. These data will be combined with qualitative data from an in-depth study of a purposive sample of eight homes (six intervention and two control). Discussion: Although process evaluations are increasingly funded alongside trials, it is still rare to see the findings published, and even rarer to see the protocol for such an evaluation published. Process evaluations have the potential to assist in interpreting and understanding trial results as well as informing future roll-outs of interventions. If such evaluations are funded they should also be reported and reviewed in a similar way to the trial outcome evaluation

Nanomechanical resonators operating as charge detectors in the nonlinear regime

We present measurements on nanomechanical resonators machined from Silicon-on-Insulator substrates. The resonators are designed as freely suspended Au/Si beams of lengths on the order of 1 - 4 um and a thickness of 200 nm. The beams are driven into nonlinear response by an applied modulation at radio frequencies and a magnetic field in plane. The strong hysteresis of the magnetomotive response allows sensitive charge detection by varying the electrostatic potential of a gate electrode.Comment: 8 pages, 6 figure

Polarized light ions and spectator nucleon tagging at EIC

An Electron-Ion Collider (EIC) with suitable forward detection capabilities would enable a unique experimental program of deep-inelastic scattering (DIS) from polarized light nuclei (deuterium 2H, helium 3He) with spectator nucleon tagging. Such measurements promise significant advances in several key areas of nuclear physics and QCD: (a) neutron spin structure, by using polarized deuterium and eliminating nuclear effects through on-shell extrapolation in the spectator proton momentum; (b) quark/gluon structure of the bound nucleon at x > 0.1 and the dynamical mechanisms acting on it, by measuring the spectator momentum dependence of nuclear structure functions; (c) coherent effects in QCD, by exploring shadowing in tagged DIS on deuterium at x << 0.1. The JLab MEIC design (CM energy sqrt{s} = 15-50 GeV/nucleon, luminosity ~ 10^{34} cm^{-2} s^{-1}) provides polarized deuterium beams and excellent coverage and resolution for forward spectator tagging. We summarize the physics topics, the detector and beam requirements for spectator tagging, and on-going R&D efforts.Comment: 6 pages, 2 figures. Prepared for proceedings of DIS 2014, XXII. International Workshop on Deep-Inelastic Scattering and Related Subjects, University of Warsaw, Poland, April 28 - May 2, 201

Polarization insensitivity of AlGaAs/GaAs interdiffused quantum wells

Modeling is used to show that interdiffusion can generate a polarization independent parabolic-like quantum well. Criteria to achieve the parabolic-like quantum wells by interdiffusion are discussed. The results indicated that interdiffused quantum wells can produce equal eigen-state spacing, polarization insensitive Stark shift and modulation characteristics similar to an ideal parabolic quantum well. The design process to obtain polarization insensitive ON- and OFF- states in the parabolic-like interdiffused quantum wells is discussed. The predicted modulation depth is comparable to those measured using parabolic quantum wells. The diffused quantum wells have the advantage of using an as-grown rectangular quantum well with post-growth annealing to tailor its confinement profile. These features suggest that the interdiffused quantum well structure can be use to produce polarization insensitive electro-absorptive modulation.published_or_final_versio

Interdiffusion contributions in optimized surface-acoustic-wave quantum-well modulators

The electro-absorption of AlGaAs/GaAs diffused quantum well (DFQW) modulator using surface acoustic wave (SAW) QW interactions was studied theoretically. The modulator was also optimized through the use of both the steeper potential at the device surface for modulation and a long λSAW and a low power SAW. The non-uniform feature of the SAW induced potential was also taken into account in optimizing the device structure. Interdiffusion took place into the W stack to modify modulation performance so that λop and the optical properties of the optimized structure can be further modified. The modulation efficiency of an incident optical field depended on the guiding properties in the QW active region.published_or_final_versio

Fully compressible simulation of low-speed premixed reacting flows

Low speed premixed combustion flows in industrial applications are generally simulated using the "incompressible" Navier-Stokes algorithms, which belong to the family of fractional step methods, or segregated methods. The approximations used for the combustion modelling in the framework of the segregated mathematical formulation, often represent important limitations for applying the combustion numerical simulation to a wider class of problems of engineering interest. Recent developments of preconditioning techniques allow to apply the same complete system of Navier-Stokes equations to a wide variety of fluid flow problems characterized by the whole range of Reynolds, Mach, Grashof, Prandtl and Damkoeler numbers. The present work describes the development of a fully "compressible" mathematical model for the simulation of low-speed turbulent premixed reactive flows. Issues on flow and fluid compressibility as well as on the two mathematical alternative formulations, are discussed. Also discussed are issues related to coupling the flamelet premixed combustion model (based on the solution of a transport equation for the progress variable) with one-equation turbulence models, instead of the classical two-equation K – ε model. In this work the model by Spalart & Allmaras is used. The several advantages brought about by the use of the fully compressible formulation are discussed based on the results obtained on a test case taken from literature

Deposition of tin oxide, iridium and iridium oxide films by metal-organic chemical vapor deposition for electrochemical wastewater treatment

In this research, the specific electrodes were prepared by metal-organic chemical vapor deposition (MOCVD) in a hot-wall CVD reactor with the presence of O2 under reduced pressure. The Ir protective layer was deposited by using (Methylcyclopentadienyl) (1,5-cyclooctadiene) iridium (I), (MeCp)Ir(COD), as precursor. Tetraethyltin (TET) was used as precursor for the deposition of SnO2 active layer. The optimum condition for Ir film deposition was at 300 °C, 125 of O2/(MeCp)Ir(COD) molar ratio and 12 Torr of total pressure. While that of SnO2 active layer was at 380 °C, 1200 of O2/TET molar ratio and 15 Torr of total pressure. The prepared SnO2/Ir/Ti electrodes were tested for anodic oxidation of organic pollutant in a simple three-electrode electrochemical reactor using oxalic acid as model solution. The electrochemical experiments indicate that more than 80% of organic pollutant was removed after 2.1 Ah/L of charge has been applied. The kinetic investigation gives a two-step process for organic pollutant degradation, the kinetic was zero-order and first-order with respect to TOC of model solution for high and low TOC concentrations, respectively

Estimating Kinetic Parameters for the Spontaneous Polymerization of Glycidol at Elevated Temperatures

The ring-opening polymerization of glycidol at elevated temperatures is investigated. To improve the synthesis of dendritic polyether polyols, experiments are carried out without initiator to identify the influence of thermal side reactions. This results in a step-growth polymerization caused by the spontaneous combination of monomers. Kinetic parameters of the side reactions are estimated by fitting simulated number- and weight-average molecular weights to the experimental values measured at different reaction times during the polymerization. The reactions are conducted at three different temperatures of 90, 105, and 120 8C. It is shown that thermal side reactions lead to high dispersities of the final product and are highly sensitive to the reactor operating temperature