bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-parametric flutter analysis of a morphing wing trailing edge
Authors: Pecora R. , Magnifico M. , Amoroso F. , Monaco E.
Published: February 2016

The development of adaptive morphing wings has been individuated as one of the crucial topics in the greening of the next generation air transport. Research programs are currently running worldwide to exploit the potentiality of morphing concepts in the optimisation of aircraft efficiency and in the consequent reduction of fuel burn. Among these, SARISTU represents the largest European funded research project which ambitiously addresses the challenges posed by the physical integration of smart concepts in real aircraft structures; for the first time ever, SARISTU will experimentally demonstrate the structural feasibility of individual morphing concepts concerning the leading edge, the trailing edge and the winglet on a full-size outer wing belonging to a CS-25 category aircraft. In such framework, the authors intensively worked on the definition of aeroelastically stable configurations for a morphing wing trailing edge driven by conventional electromechanical actuators. Trade off aeroelastic analyses were performed in compliance with CS-25 airworthiness requirements (paragraph 25.629, parts (a) and (b)-(1)) in order to define safety ranges for trailing-edge inertial and stiffness distributions as well as for its control harmonics. Rational approaches were implemented in order to simulate the effects induced by variations of trailing-edge actuators’ stiffness on the aeroelastic behaviour of the wing also in correspondence of different dynamic properties of the trailing-edge component.
Reliable aeroelastic models and advanced computational strategies were properly implemented to enable fast flutter analyses covering several configuration cases in terms of structural system parameters. Already available finite elements models were processed in MSC-NASTRAN® environment to evaluate stiffness and inertial distributions suitable for the stick-equivalent idealisation of the reference structure. A parametric stick-equivalent model of the reference structure was then generated in SANDY3.0, an in-house developed code, that was used for the definition of the coupled aero-structural model as well as for the solution of aeroelastic stability equations by means of theoretical modes association in frequency domain.

Obtained results were finally arranged in stability carpet plots efficiently conceived to provide guidelines for the preliminary design of the morphing trailing-edge structure and therein embedded actuators.
Self-cleaning barrier filter for rotorcraft engines
Authors: Bojdo N. , Filippone A.
Published: February 2016

A parameter-based study of a novel self-cleaning barrier filter concept for rotorcraft engines is presented. Existing engine inlet barrier filters for rotorcraft achieve a high separation efficiency (up to 99% for a dust resembling a coarse test dust) at the expense of a pressure drop that increases over time. Other engine protection devices with invariant pressure loss signals cannot offer the same level of efficiency. Furthermore, inlet barrier filters are absent on rotorcraft with larger mass flow demands, due to larger filtration area required. This work proposes a solution that addresses each of these limitations, and establishes the parametric framework upon which such a design could be realised. The drum-shaped self-cleaning barrier filter is affixed to the engine inlet and spins about its longitudinal axis, such that each of its fibrous filter pleats can be cleaned once per cycle. An initial increase of pressure loss gives way to a period of sustained invariance. The key parameters are the internal particle capacity of the chosen filter medium and the speed of rotation. Other design parameters can be optimised to yield minimum pressure drop for given set of flow conditions.
Qualification of the ARA TWT for laminar flow testing
Authors: Allen N. , Lawson S. , Maina M. , Alderman J.
Published: February 2016

The current drive towards reducing the environmental impact of aircraft necessitates the ability to evaluate techniques for promoting natural laminar flow in a large scale wind tunnel facility. A test was undertaken on the M2355 variable sweep model to obtain temperature sensitive paint (TSP) and hot-film data from which the transition locations at a range of sweep angles and flow conditions could be identified. The TSP technique has been shown to be a reliable method for determining transition on suitably treated wind tunnel models. Pressure data were also acquired and interpolated to provide the input to the laminar boundary layer code, BL2D, the output from which was used in the linear stability analysis code, CoDS, to calculate the N-factor for the ARA TWT (Transonic Wind Tunnel) facility. Two sets of N-factors were calculated, firstly using incompressible analysis with stationary crossflow and secondly using compressible analysis with travelling crossflow. In both analyses the Tollmien-Schlichting and crossflow cases were calculated together, rather than separating the cases before running the analysis. The resulting N-factors indicate a degree of scatter typical for experimental data. The N-factor based on incompressible theory for crossflow was found to be approximately 7 and for Tollmien-Schlichting (T-S), approximately 11. The results of the wind tunnel test and the analysis carried out are considered to be the first steps towards establishing a methodology for performance testing, in atmospheric tunnels such as the TWT, for aircraft designed to have significant regions of laminar flow. The project has also provided a body of experimental test data which will be valuable for future research into development and validation of laminar flow methods.
Structural health monitoring technology for a full-scale aircraft structure under changing temperature
Authors: Gao D. , Wang Y. , Wu Z. , Rahim G.
Published: February 2016

This paper presents optimal operating modes for the factors to maximise the detection capability of a given SHM technology in service environment. Firstly, an orthogonal experiment was performed to determine the importance ranking of the influence factors. Through the test, it is found that operating temperatures for SHM hardware and excitation frequencies for PZT actuator were the most critical factors. Then, numerical model of Lamb waves generated and received by PZT sensors were presented to predict the distribution of response signal amplitudes under changing temperature. Verification tests were carried out on a glass fibre reinforced composite plate at different temperatures. The comparison between the analytical prediction and test results was presented and temperature-dependent optimal frequencies for PZT actuators were obtained. Finally, SHM experiments of full-scale horizontal composite structures are presented. The detection capability of the SHM technology applications of aircrafts in real world is verified by the experimental results.
Optimising the roll-sway motion cues available from a short stroke hexapod motion platform
Authors: Hodge S.J. , Perfect P. , Padfield G.D. , White M.D.
Published: February 2016

This paper presents findings from research conducted at the University of Liverpool aimed at optimising the motion cues available from a short-stroke hexapod motion platform. Piloted simulations were conducted for a typical helicopter low-speed sidestep manoeuvre. To correctly simulate the sidestep manoeuvre the motion platform must translate laterally at the same time as it rolls. If the motion in these two axes is not properly harmonised then the pilot can experience significant false motion cues. This is a particular concern for short-stroke hexapod platforms, where displacement limits can severely constrain the available lateral travel particularly during motion in multiple axes (e.g. roll and sway). During the experiment the motion filter gains in the roll and sway axes and the roll-axis motion filter break-frequency were varied. Objective and subjective measures of pilot performance and motion fidelity were gathered for each motion filter configuration, the latter using a new motion fidelity rating scale. The key findings show that acceptable motion cues could only be achieved by careful harmonisation of the motion filter gains in the roll and sway axes. A high gain in the roll axis coupled with a low gain in the sway axis resulted in motion which was abrupt and uncomfortable. On the other hand, too large a gain in the sway axis resulted in extreme lateral displacements of the motion platform leading to undesirable side-effects. The phase distortion between the visual and platform motion cues, introduced by the roll-axis motion filter, also had a significant impact on the pilot’s perception of motion fidelity. These results are presented in the form of proposed motion fidelity criteria for short-stroke hexapod platforms and compared with results from previous research conducted on a range of large motion systems.
An integrated methodology to assess the operational and environmental performance of a conceptual regenerative helicopter
Authors: Ali F. , Goulos I. , Pachidis V.
Published: February 2016

This paper aims to present an integrated multidisciplinary simulation framework, deployed for the comprehensive assessment of combined helicopter–powerplant systems at mission level. Analytical evaluations of existing and conceptual regenerative engine designs are carried out in terms of operational performance and environmental impact. The proposed methodology comprises a wide-range of individual modeling theories applicable to helicopter flight dynamics, gas turbine engine performance as well as a novel, physics-based, stirred reactor model for the rapid estimation of various helicopter emissions species. The overall methodology has been deployed to conduct a preliminary trade-off study for a reference simple cycle and conceptual regenerative twin-engine light helicopter, modeled after the Airbus Helicopters Bo105 configuration, simulated under the representative mission scenarios. Extensive comparisons are carried out and presented for the aforementioned helicopters at both engine and mission level, along with general flight performance charts including the payload-range diagram. The acquired results from the design trade-off study suggest that the conceptual regenerative helicopter can offer significant improvement in the payload-range capability, while simultaneously maintaining the required airworthiness requirements. Furthermore, it has been quantified through the implementation of a representative case study that, while the regenerative configuration can enhance the mission range and payload capabilities of the helicopter, it may have a detrimental effect on the mission emissions inventory, specifically for NOx(Nitrogen Oxides). This may impose a trade-off between the fuel economy and environmental performance of the helicopter. The proposed methodology can effectively be regarded as an enabling technology for the comprehensive assessment of conventional and conceptual helicopter-powerplant systems, in terms of operational performance and environmental impact as well as towards the quantification of their associated trade-offs at mission level.
Water injection pre-compressor cooling assist space access
Authors: Mehta U. , Bowles J. , Melton J. , Huynh L. , Hagseth P.
Published: February 2016

Advances in space activity are linked to reductions in launch cost. Air-breathing propulsion-assisted flight systems offer the potential for revolutionary change of the space operations paradigm. Horizontal launch of a space-access system provides mission flexibility, responsiveness, and affordability. One way to reduce launch cost is to increase the Mach number at which a launch vehicle is staged from a carrier aircraft. Without exceeding the engine and airframe design limits, the pre-compressor cooling technology allows an operational aircraft to operate at Mach numbers and altitudes beyond its basic operational limits. This is an essential, near-term technology for reducing launch cost to place small-weight payloads in low Earth orbit. The advantage of this technology is assessed with a modified McDonnell Douglas QF-4C aircraft. Payloads are unachievable or marginal with an unmodified QF-4C. However, payloads weighing around 150 pounds are plausible with this aircraft when incorporating the water injection pre-compressor cooling (WIPCC) technology.
Flight in nature II: How animal flyers land
Authors: Manzanera R.A. Jiménez , Smith SH.
Published: February 2016

In this review paper, different landing strategies of diverse species of animal flyers and gliders, both extinct and extant, are analysed. These methods vary depending on the animal group and the sensory system used by the animal to detect its landing site. In almost all species the use of delayed stall during the landing manoeuvre was observed. Sometimes wing flapping was used to aid in deceleration. With respect to guidance and navigation, most insect, bird and mammal gliders use their vision to guide them to landing via optical flow or motion parallax. Bats, which are nocturnal creatures, rely on their auditory system as they use echolocation to find their nesting site. Some butterfly and moth species guide themselves to landing using their olfactory sense as they follow pheromone trails. The information presented here can be used as a source of information for novel bio-inspired unmanned aircraft design.
Flexible rotor blade dynamics for helicopter aeromechanics including comparisons with experimental data
Authors: Goulos I. , Pachidis V. , Pilidis P.
Published: February 2016

This paper presents the development of a mathematical model for the implementation of flexible rotor blade dynamics in real-time helicopter aeromechanics applications. A Lagrangian approach is formulated for the rapid estimation of natural vibration characteristics of nonuniform rotor blades. A matrix/vector formulation is proposed for the treatment of elastic blade kinematics in the time-domain. In order to overcome the classical hurdles of time-accurate simulation and establish applicability in real-time, a novel, second-order accurate, finite-difference scheme is employed for the numerical discretisation of elastic blade motion. The proposed rotor dynamics model is coupled with a finite-state induced flow and an unsteady blade element aerodynamics model. The combined formulation is implemented in a helicopter flight mechanics simulation code. The integrated approach is deployed in order to investigate rotor blade resonant frequencies, trim control angles, oscillatory blade loads and induced vibration for a hingeless and an articulated helicopter rotor. Extensive comparisons are carried out with wind tunnel and flight test measurements, and non-real-time comprehensive analysis methods. Good agreement with measured data is exhibited considering primarily the low-frequency harmonic components of oscillatory loading. It is shown that, the developed methodology can be utilised for real-time simulation on a typical computer with sufficient modelling fidelity for accurate estimation of oscillatory blade loads.
The effect of the aerofoil thickness on the performance of the MAV scale cycloidal rotor
Authors: Hu Y. , Zhang H.L. , Tan C.
Published: February 2016

The numerical simulations for cycloidal propellers based on five aerofoils with different thickness are presented in this paper. The CFD simulation is based on sliding mesh and URANS. The results of CFD simulation indicates that all test cases share similar flow pattern. There are leading edge vortex and trailing-edge vortex due to blade dynamic stall. Interaction between the vortices shed from upstream blade and the downstream blade can be observed. There is variation of blade relative inflow velocity due to downwash in the cycloidal rotor cage. These factors result in large fluctuations of the aerodynamics forces on the blade. The comparison of the forces and flow pattern indicates that the thickness and leading edge radius of the aerofoil can significantly influent the flow pattern and hence the performance of the cycloidal propeller.
Instrumented splashdown testing of a scale model Titan Mare Explorer (TiME) capsule
Authors: Lorenz R. D. , Hibbard K. , Paul M. V. , Walsh J. , Olds D. W. , Willits S. , Bierhaus E. B. , Kretsch W. E.
Published: February 2016

Water entry tests are conducted with a scale model capsule to explore the sensitivity of splashdown accelerations and motions to impact conditions, to support estimation of splashdown loads and behaviours of the proposed Titan Mare Explorer (TiME) mission. A 3D printed capsule with off-the-shelf USB accelerometer loggers enabled tests to be performed on a tight schedule. Contact impulse and peak loads are presented for a range of impact speeds and geometries, and predicted loads at full-scale on Titan are derived. The observed variation of peak load with impact speed is broadly consistent with the theoretically-expected square law but is surprisingly also consistent with a linear function (in common with some results from the literature). Test execution procedures and the performance of the data acquisition system are reviewed.
Turboprop aircraft noise: Advancements and comparison with flyover data
Authors: Filippone A.
Published: February 2016

This paper contributes to the prediction of aircraft noise. The framework of our study is based on a comprehensive analysis, which includes sub-models for airframe, propulsion and propeller noise. The sources models are complemented by various accounts of interference phenomena, including fuselage scattering, propeller shielding, wing and flap effects. The propagation of the acoustic pressures from the noise sources is done through a number of additional sub-models, which include spherical spreading, Doppler effects, ground reflection, shear winds and temperature gradients through the atmosphere. We present some fly-over noise data. The data include measurements by 13 microphones at community locations, meteorological data, and flight recorder data packs, which provide the complete state of the aircraft along the noise trajectory. Examples of verification are shown for the turboprop airplane Dash8-Q400, both on approach and departure. A sensitivity analysis is carried out to investigate the importance of the uncertainty effects, which are split between internal (aircraft and propulsion), external (atmospheric environment), and aircraft position.
Experimental investigation of the rotor-wing aerodynamic interaction in a tiltwing aircraft in hover
Authors: Droandi G. , Zanotti A. , Gibertini G. , Grassi D. , Campanardi G.
Published: February 2016

The hovering performance and the lifting capability of tiltrotor aircraft are strongly affected by the aerodynamic interaction between wing and rotors. The tiltwing concept represents a promising technology to increase the hover performance by reducing the wing-rotor interference. The present work describes an experimental activity carried out on a ¼ scaled tiltwing aircraft half-model to achieve a detailed insight about the main issues characterising the aerodynamic interaction between wing and rotor in hover. The results of the experimental campaign, including both force measurements and Particle Image Velocimetry surveys, enabled to evaluate both the aircraft performance for different configurations of the tilting wing and to achieve a detailed insight about the flow physics of the rotor wake in the interaction with the wing. The test activity provided a comprehensive experimental database that was obtained over a not confidential aircraft configuration.
Numerical investigation of secondary flows in a constant-width wind-tunnel contraction
Authors: Bouriga M. , Taher R. , Morency F. , Weiss J.
Published: February 2016

The flow inside a constant-width wind-tunnel contraction is simulated by solving the Reynolds-Averaged Navier-Stokes equations with an eddy-viscosity turbulence model. The results show the presence of longitudinal vortices near the sidewalls centreline. This confirms a former hypothesis involving the generation of skew-induced longitudinal vorticity within the sidewalls boundary layers. Detailed analysis reveals that the flow structure is influenced by viscous effects in the boundary layers and streamline curvature in the potential flow. Three-dimensional boundary-layer profiles on the contraction sidewall are analysed in the framework of the streamline co-ordinate system and its associated hodographic diagram. The resulting profiles help understand the generation of secondary flows and the associated longitudinal vorticity.
Effects of surface flow visualisation on aerodynamic loads at low Reynolds number
Authors: Traub L. W. , Waghela R. , Botero E. M.
Published: February 2016

In this article, the effect of on-surface flow visualisation (SVF) techniques on measured loads over an airfoil are explored. Titanium dioxide based mixture effects on the lift and drag coefficient are experimentally quantified at low Reynolds numbers by recording the time history as the patterns evolve and freeze. With statistical comparison based on Student’s t-distribution method, it was determined that the effect on the drag coefficient was minimal but the lift coefficient was slightly attenuated. Additionally, it was observed that at high angles-of-attack the temporal history of the flow as the wind tunnel ramps up may alter the steady-state flow field in the presence of a SFV mixture.
Experimental and numerical study of mixing characteristics of a rectangular lobed mixer in supersonic flow
Authors: Feng J.-H. , Shen C.-B. , Wang Q.-C. , Lei J.
Published: February 2016

A combined experimental and computational study on a rectangular lobed mixer is performed. A series of simulations based on a steady Reynolds-averaged Navier-Stokes Simulation (RANS) are conducted to analyse the mixing mechanisms of large-scale streamwise structure shed by the trailing edge of lobed mixer, with emphasis being placed on the effect of turbulence modeling and inflow conditions. The simulations are validated in respect of velocity and scalar distribution against the data obtained through Particle Image Velocimetry (PIV) and Nanoparticle-based Planar Laser Scattering (NPLS) technique. The computational results predicted by the SSTk–ω turbulence model show better agreement with the experimental data. But the small-scale turbulence structures are not captured accurately by these turbulence models. The convoluted shear layer shed from trailing edge is stretched and rotated by the large-scale streamwise vortices, forming an unstable ‘pinching-off’ structure, which increases the interfacial area. And at the interface of two streams, a large number of small-scale turbulence structures are formed, which contribute a lot to the mixing enhancement along with the increased interfacial area. The streamwise vorticity decays more rapidly with the decrease of velocity ratio and total pressure ratio of two streams. The scalar thickness which reflects the mixing rate of two streams increases with the decreasing velocity ratio and total pressure ratio.
Aerodynamic modelling of fin stabilised underslung loads
Authors: Enciu K. , Rosen A.
Published: February 2016

Box-like slung loads exhibit periodic yaw response instabilities, while carried externally by a helicopter. When coupled with the slung load longitudinal and lateral pendulum motions, these instabilities result in significant pendulum oscillations of the load. High amplitude oscillations lead in many cases to the limiting of a load’s flight envelope. Using wind tunnel and flight tests, rear mounted fins were previously demonstrated as efficient means for stabilisation of a problematic load. However, the lack of a proper analytical model of the stabilised load’s aerodynamic characteristics, led to a trial and error development process, without an appropriate physical understanding of the stabilisation problem. The present paper describes a method for the aerodynamic modeling of fins stabilised slung loads based on a limited number of simple static wind-tunnel tests. The resulting database is incorporated in a dynamical slung load simulation that shows good agreement with dynamic wind-tunnel tests. The applicability of the proposed method is demonstrated, by the calculation of stabilised loads aerodynamic databases for interim fin inclination angles not covered by tests.
Autonomous visual recognition of known surface landmarks for optical navigation around asteroids
Authors: Rowell N. , Dunstan M. N. , Parkes S. M. , Gil-Fernández J. , Huertas I. , Salehi S.
Published: February 2016

We present an autonomous visual landmark recognition and pose estimation algorithm designed for use in navigation of spacecraft around small asteroids. Landmarks are selected as generic points on the asteroid surface that produce strong Harris corners in an image under a wide range in viewing and illumination conditions; no particular type of morphological feature is required. The set of landmarks is triangulated to obtain a tightly fitting mesh representing an optimal low resolution model of the natural asteroid shape, which is used onboard to determine the visibility of each landmark and enables the algorithm to work with highly concave bodies. The shape model is also used to estimate the centre of brightness of the asteroid and eliminate large translation errors prior to the main landmark recognition stage. The algorithm works by refining an initial estimate of the spacecraft position and orientation. Tests with real and synthetic images show good performance under realistic noise conditions. Using simulated images, the median landmark recognition error is 2m, and the error on the spacecraft position in the asteroid body frame is reduced from 45m to 21m at a range of 2km from the surface. With real images the translation error at 8km to the surface increases from 107m to 119m, due mainly to the larger range and lack of sensitivity to translations along the camera boresight. The median number of landmarks detected in the simulated and real images is 59 and 44 respectively. This algorithm was partly developed and tested during industrial studies for the European Space Agency’s Marco Polo-R asteroid sample return mission.
Biased optimal guidance law with specified velocity rendezvous angle constraint
Authors: Xu X. , Liang Y.
Published: February 2016

In order to increase the effectiveness of interceptor missile, velocity rendezvous angle control is required in the terminal phase. The purpose of this paper is to obtain an optimal guidance law which can achieve specified velocity rendezvous angle as well as zero terminal miss distance. A biased optimal guidance law based on a simplified mathematical model is deduced for interceptors engaging against invasion aircraft. Different from previous literatures on this issue, the presented guidance law suitable for intercepting high-speed maneuvering target. Another advantage is, under centimeter level miss distance setting, the guidance law needs smaller guidance command near the terminal time, which can successfully avoid command saturation. Simulation results demonstrate the effectiveness of the presented guidance law.
Numerical investigation of symmetry breaking and multi-loop hysteresis phenomena in a symmetric supersonic combustor
Authors: Cui T. , Liu Z.
Published: February 2016

Numerical investigations are performed to study the features of symmetry breaking phenomena in a symmetric supersonic combustor. By changing the fuel equivalence ratio, the symmetry breaking phenomena are numerically observed. Further, the hysteresis behaviours are observed along with the phenomena of symmetry breaking by increasing and then decreasing the the fuel equivalence ratio. Furthermore, more complex hysteresis phenomenon, i.e., multi-loop hysteresis, is observed numerically. The multi-loop hysteresis consists of both major and minor loops, and is associated with the interaction between multiple flow structures. Due to the fact that different flow structures would result in different flow conditions, the findings regarding the existence of hysteresis behaviours can significantly affect the combustion process and even the performance of the engine. It is hoped that the observation of the (multi-loop) hysteresis phenomenon may bring it to the attention of those investigators whose experiments maybe affected by its occurrence.
Consideration of structural constraints in passive rotor blade design for improved performance
Authors: Lim J. W.
Published: February 2016

This design study applied parameterisation to rotor blade for improved performance. In the design, parametric equations were used to represent blade planform changes over the existing rotor blade model. Design variables included blade twist, sweep, dihedral, and radial control point. Updates to the blade structural properties with changes in the design variables allowed accurate evaluation of performance objectives and realistic structural constraints – blade stability, steady moments (flap bending, chord bending, and torsion), and the high g manoeuvring pitch link loads. Performance improvement was demonstrated with multiple parametric designs. Using a parametric design with advanced aerofoils, the predicted power reduction was 1·0% in hover, 10·0% at μ = 0·30, and 17·0% at μ = 0·40 relative to the baseline UH-60A rotor, but these were obtained with a 35% increase in the steady chord bending moment at μ = 0·30 and a 20% increase in the half peak-to-peak pitch link load during the UH-60A UTTAS manoeuvre Low vibration was maintained for this design. More rigorous design efforts, such as chord tapering and/or structural redesign of the blade cross section, would enlarge the feasible design space and likely provide significant performance improvement.
Magnetoacoustic solitons and shocks in dense astrophysical plasmas with relativistic degenerate electrons
Authors: Irfan M. , Ali S. , Mirza Arshad M.
Published: February 2016

Two-fluid quantum magnetohydrodynamic (QMHD) equations are employed to investigate linear and nonlinear properties of the magnetosonic waves in a semi-relativistic dense plasma accounting for degenerate relativistic electrons. In the linear analysis, a plane wave solution is used to derive the dispersion relation of magnetosonic waves, which is significantly modified due to relativistic degenerate electrons. However, for a nonlinear investigation of solitary and shock waves, we employ the reductive perturbation technique for the derivation of Korteweg–de Vries (KdV) and Korteweg–de Vries Burger (KdVB) equations, admitting nonlinear wave solutions. Numerically, it is shown that the wave frequency decreases to attain a lowest possible value at a certain critical number density $N_{c}^{(0)}$, and then increases beyond $N_{c}^{(0)}$ as the plasma number density increases. Moreover, the relativistic electrons and associated pressure degeneracy lead to a reduction in the spatial extents of the magnetosonic waves and a strengthening of the shock amplitude. The results might be important for understanding the linear and nonlinear magnetosonic excitations in dense astrophysical plasmas, such as in white dwarfs, magnetars and neutron stars, etc., where relativistic degenerate electrons are present.
Some Effects of Rice Quality on Rough Rice Prices
Authors: Brorsen B. Wade , Grant Warren R. , Rister M. Edward
Published: February 2016

Quality discounts and premiums for rough rice in Texas rice bid/acceptance markets are analyzed. The most important quality factors determining the value of rough rice are head yield and peck. A one percentage point reduction in peck damage raises the price received per hundredweight of rough rice by $.13 to $.68 across markets and years. Since peck damage can be reduced by controlling the rice stinkbug, evaluation of alternative methods for better control of this pest in Texas rice fields is needed.
Differences in the quality of life of two groups of drug users
Authors: Rooney Siobhan , Freyne Aideen , Kelly Gabrielle , O'Connor John
Published: February 2016

Objectives: The aim of this study was to compare aspects of the quality of life of drug users on a methadone maintenance programme to drug users on a harm minimisation programme.

Method: Thirty-six clients attending the harm minimisation programme in the National Drug Treatment Centre, Dublin, were matched for age and sex to 36 clients on the methadone maintenance programme. All were interviewed with the SF-36 Health Survey Questionnaire to measure health related quality of life and with the Hospital Anxiety and Depression Scale (HADs) to measure psychological morbidity.

Results: More clients from the harm minimisation programme had previous psychiatric problems than clients on the methadone maintenance programme, with an odds ratio of 4.3 CI(1.2,15.2). On the HADs, clients on the methadone maintenance programme had significantly lower depression scores than clients on the harm minimisation programme. In addition more clients on the harm minimisation programme were severely depressed than clients on the methadone maintenance programme. On the UK SF-36 Scale, clients on the harm minimisation programme perceived a significantly greater deterioration in ‘change in health’ over the previous year than clients on the methadone maintenance programme.

Conclusions: Although clients on a methadone maintenance programme had an improved perception of their quality of life in relation to psychological and overall health function from the previous year, compared to clients on a harm minimisation programme, there still existed varying degrees of psychopathology in both groups which need to be considered when providing future services for drug users.
Whole genome sequencing reveals extensive community-level transmission of group AStreptococcusin remote communities
Authors: BOWEN A. C. , HARRIS T. , HOLT D. C. , GIFFARD P. M. , CARAPETIS J. R. , CAMPBELL P. T. , McVERNON J. , TONG S. Y. C.
Published: February 2016

Impetigo is common in remote Indigenous children of northern Australia, with the primary driver in this context beingStreptococcus pyogenes[or group AStreptococcus(GAS)]. To reduce the high burden of impetigo, the transmission dynamics of GAS must be more clearly elucidated. We performed whole genome sequencing on 31 GAS isolates collected in a single community from children in 11 households with ⩾2 GAS-infected children. We aimed to determine whether transmission was occurring principally within households or across the community. The 31 isolates were represented by nine multilocus sequence types and isolates within each sequence type differed from one another by only 0–3 single nucleotide polymorphisms. There was evidence of extensive transmission both within households and across the community. Our findings suggest that strategies to reduce the burden of impetigo in this setting will need to extend beyond individual households, and incorporate multi-faceted, community-wide approaches.
Exclusive Burial Rights
Authors: Sparkes Peter
Published: February 2016

A distressing example of double conveyancing came to light inReed v Madon. A family had purchased exclusive rights of burial in a private burial ground, but one of the plots was resold, and a burial under this second title occurred before the original grantees had time to object. On the facts, the loss of the exclusive burial right could be effectively compensated in damages. This removed the need for Morritt J. to rule on some of the interesting points of law raised by exclusive burial rights. There was no authority concerned solely with a private burial ground. It was necessary therefore to argue by analogy from corresponding rights granted in other burial places, especially churchyards. It is now proposed to explore these issues.
Discontinuing Life Support in an Infant of a Drug-Addicted Mother: Whose Decision Is It?
Authors: Jain Renu , Thomasma David C.
Published: February 2016

“Ethical dilemmas…are rarely simple and stark but are, instead, multifaceted, complex, and gut wrenching for parents and care givers alike.” This is never more the case than when one must treat vulnerable babies who are not, nor ever can be competent to offer us some guidance about that treatment. The ethical problems are heightened when the parents, or the single mother, are incompetent to make decisions themselves, for example, because of drug addiction. In such cases, when the baby is premature and suffering the effects of the drugs the mother has taken, and the mother herself is either no longer available for consultation or so damaged by her own addiction that she is not a reliable decisionmaker, the usual trend In the United States is to initiate treatment and continue until it is virtually certain that the infant will die.
Core Temperature Monitoring of Firefighters During Hazardous Materials Training Sessions
Authors: Menze Roger , McMullen Mary Jo , White Lynn J. , Dougherty James M.
Published: February 2016

Objective:

To determine core temperature (Tc) elevations in hazardous materials (HazMat) technicians wearing level-A fully encapsulated, chemically resistive suits (FECRSs) during training scenarios.

Design:

Cross-sectional, observational feasibility study with Institutional Review Board approval.

Setting:

HazMat training scenarios held during the summer of 1994. Weather conditions included both rainy and sunny days, with a mean ambient temperature of 75.8°F(24.3°C) (range 69–83° F [20.6–28.3°C).

Participants:

Nine male firefighters participating in training scenarios in the Midwestern United States.

Interventions:

Each volunteer swallowed a capsule containing a Tc sensor developed by the National Aeronautics and Space Administration. The capsule continuously monitored Tc and stored data in an ambulatory recorder worn under the level-A FECRS during training.

Results:

Mean age of the volunteers was 34 years, mean weight was 92.6 kg, and average baseline Tc was 36.7°C (97.1°F) (range 35.3–38.2°C [95.5–100°F]). Time in the FECRS averaged 25.4 minutes (range 14–35 minutes). All subjects demonstrated increased Tc while in the suit; the mean Tc increase was 0.8°C (1.4°F) (range 0.2–1.3°C [0.4–2.3°F]). The Tc continued to increase during wet decontamination procedures and after suit removal. Mean heat storage values (ΔTcx LBMx 3.47 kJ) were calculated, and found to be moderately elevated to 3.6 kJ/kg (range 2.1–4.6 kJ/kg).

Conclusion:

These observations support the validity and significance of implementing prophylactic measures for firefighters using protective clothing. Simple protective measures include enforced time limitations, hydration, and efforts to minimize heat buildup by avoiding both direct sunlight and unnecessary time encapsulated in the suit.
Turning on the Lights: A Meta-Analysis of Residential Electricity Demand Elasticities
Authors: Espey James A. , Espey Molly
Published: February 2016

Meta-analysis is used to quantitatively summarize previous studies of residential electricity demand to determine if there are factors that systematically affect estimated elasticities. In this study, price and income elasticities of residential demand for electricity from previous studies are used as the dependent variables, with data characteristics, model structure, and estimation technique as independent variables, using both least square estimation of a semilog model and maximum likelihood estimation of a gamma model. The findings of this research can help better inform public policy makers, regulators, and utilities about the responsiveness of residential electricity consumers to price and income changes.
ON THE EXCEPTIONAL SPECIALIZATIONS OF BIG HEEGNER POINTS
Authors: Castella Francesc
Published: February 2016

We extend the$p$-adic Gross–Zagier formula of Bertoliniet al.[Generalized Heegner cycles and$p$-adic Rankin$L$-series,Duke Math. J.162(6) (2013), 1033–1148] to the semistable non-crystalline setting, and combine it with our previous work [Castella, On the$p$-adic variation of Heegner points, Preprint, 2014,arXiv:1410.6591] to obtain a derivative formula for the specializations of Howard’s big Heegner points [Howard, Variation of Heegner points in Hida families,Invent. Math.167(1) (2007), 91–128] at exceptional primes in the Hida family.
MOVABLE EMPIRE: LABOR, MIGRATION, AND U.S. GLOBAL POWER DURING THE GILDED AGE AND PROGRESSIVE ERA
Authors: Greene Julie
Published: February 2016

The acquisition of an empire that stretched across North America, the Caribbean, Central America, and the Pacific world transformed the United States during the Gilded Age and Progressive Era. While scholars have examined many aspects of U.S. expansionism, a neglected issue involved the imperial labor migrations it required. From across North America, the Caribbean, southern Europe, and Asia, men and women were recruited to labor in the service of building U.S. global power at the turn of the twentieth century. Officials saw recruiting and moving laborers from far away as necessary to ensure productivity and discipline. This required U.S. government and corporate leaders to experiment with labor management in ways that shaped the “long twentieth century” of U.S. history. Mobility was not only central to the logic of the U.S. Empire; when possible, workers also deployed it for their own ends. Therefore migration became a terrain of struggle between workers and government officials. This paper looks in particular at documents generated by two migrating groups important in the making of U.S. global power. Afro-Caribbeans who traveled to construct the Panama Canal; and soldiers who served in the War of 1898 and the Philippine-American War.
ROOSEVELT'S MAN IN EUROPE
Authors: Weisbrode Kenneth
Published: February 2016

Lewis Einstein (1877–1967) was a little-known diplomat who became one of Theodore Roosevelt's closest advisers on European affairs. Roosevelt's attraction to Einstein derived not only from a keen writing style and considerable fluency in European history, literature and politics, but also from his instinct for anticipating the future of European rivalries and for the important role the United States could play there in preserving peace. The two men shared a perspective on the twentieth century that saw the United States as a central arbiter and enforcer of international order—a position the majority of Americans would accept and promote only after the Second World War. The relationship between Roosevelt and Einstein sheds light on the rising status of American diplomacy and diplomats and their self-image vis-à-vis Europe at the turn of the twentieth century.
STRENUOUS COMPETITION ON THE FIELD OF PLAY, DIPLOMACY OFF IT: THE 1908 LONDON OLYMPICS, THEODORE ROOSEVELT AND ARTHUR BALFOUR, AND TRANSATLANTIC RELATIONS
Authors: Rofe J. Simon , Tomlinson Alan
Published: February 2016

The Olympic sporting context of 1908, with its tension between nationalistic competition and high-minded amateurism, provides insight as well into the transatlantic relationship between Great Britain and the United States during the presidency of Theodore Roosevelt and in the years following the prime ministerial tenure of Britain's Arthur Balfour. The article explores this relationship through two high-profile sports events—the 1908 London Olympic Games and its predecessor games in St. Louis in 1904—to consider how governing political and social networks in the two countries viewed themselves and one another and related to one another. The positions and values of U.S. President Theodore Roosevelt and British Prime Minister Arthur Balfour are reevaluated in this context. The article concludes that the 1908 Olympics in many ways typified Anglo-American relations during the opening decade of the twentieth century. Strenuous competition between the two nations was accepted by both parties as a means to achieve a measure of superiority over the other for the broader audience in each nation and also across the globe.
Mundspülung bei oraler Mukositis im Kontext der allogenen Stammzell-Transplantation
Authors: Kröner Anja , Aerts Erik , Schanz Urs , Spirig Rebecca
Published: February 2016

Zusammenfassung. Hintergrund: Die orale Mukositis ist eine häufige Komplikation bei allogenen Stammzell-Transplantationen, die zu erhöhter Morbidität und Mortalität und höheren Kosten führen kann und Einfluss auf die Lebensqualität der Patienten hat. Auf der Stammzell-Transplantationsstation eines schweizerischen Universitätsspitals werden die Patienten nach aktuellen Richtlinien zur Mundspülung angeleitet und ihr Mundstatus wird täglich erfasst. Forschungsfrage: Wie erleben die Patienten die orale Mukositis und welche Faktoren beeinflussen ihr Verhalten, die Mundspülung regelmäßig durchzuführen? Methode: In diesem qualitativen Teil einer simultan eingebetteten Mixed Methods Studie wurden 14 Patienten mittels Leitfadeninterviews befragt. Zur Datenauswertung wurde die qualitative Inhaltsanalyse eingesetzt. Ergebnisse: Die Resultate zeigen, dass sich die orale Mukositis nicht losgelöst von Krankheit, Isolation und Betreuung betrachten lässt. Sie war nur für Patienten mit einer starken Ausprägung eine große Belastung, sonst standen andere Symptome im Vordergrund. Für die regelmäßige Mundspülung, welche eine der wichtigsten präventiven Maßnahmen ist, wurden motivierende und hemmende Faktoren genannt. Schlussfolgerungen: Die Studie zeigt auf, wie wichtig es ist, die orale Mukositis im Zusammenhang mit der gesamten Transplantation zu sehen, aber auch, dass das Wissen um motivierende und hemmende Faktoren die Pflegenden bei der Betreuung der Patienten unterstützen kann. Die Förderung des Selbstmanagements ist dabei ein wichtiger Schwerpunkt.
Unfolded protein response-induced dysregulation of calcium homeostasis promotes retinal degeneration in rat models of autosomal dominant retinitis pigmentosa
Authors: Shinde V , Kotla P , Strang C , Gorbatyuk M
Published: February 2016

The molecular mechanism of autosomal dominant retinitis pigmentosa (ADRP) in rats is closely associated with a persistently activated unfolded protein response (UPR). If unchecked, the UPR might trigger apoptosis, leading to photoreceptor death. One of the UPR-activated cellular signaling culminating in apoptotic photoreceptor cell death is linked to an increase in intracellular Ca2+. Therefore, we validated whether ADRP retinas experience a cytosolic Ca2+ overload, and whether sustained UPR in the wild-type retina could promote retinal degeneration through Ca2+-mediated calpain activation. We performed an ex vivo experiment to measure intracellular Ca2+ in ADRP retinas as well as to detect the expression levels of proteins that act as Ca2+ sensors. In separate experiments with the subretinal injection of tunicamycin (UPR inducer) and a mixture of calcium ionophore (A231278) and thapsigargin (SERCA2b inhibitor) we assessed the consequences of a sustained UPR activation and increased intracellular Ca2+ in the wild-type retina, respectively, by performing scotopic ERG, histological, and western blot analyses. Results of the study revealed that induced UPR in the retina activates calpain-mediated signaling, and increased intracellular Ca2+ is capable of promoting retinal degeneration. A significant decline in ERG amplitudes at 6 weeks post treatment was associated with photoreceptor cell loss that occurred through calpain-activated CDK5-pJNK-Csp3/7 pathway. Similar calpain activation was found in ADRP rat retinas. A twofold increase in intracellular Ca2+ and up- and downregulations of ER membrane-associated Ca2+-regulated IP3R channels and SERCA2b transporters were detected. Therefore, sustained UPR activation in the ADRP rat retinas could promote retinal degeneration through increased intracellular Ca2+ and calpain-mediated apoptosis.