bluuebunny/crossref_metadata_2025 huggingface dataset:
Directed crystallization of glass‐coated microwires
Authors: Larin V. , Panina L. V. , Patroi E.‐A. , Patroi D. , Bashev V. , Kutseva N.
Published: February 2016

In this work, the directed crystallization of glass‐coated magnetic microwires of Co‐rich composition is realized with the aim to develop a novel technique for micro‐magnet fabrication. The onset of the process is caused by local overheating above the primary crystallization temperature while the rest of the wire sample is at the temperature slightly below the crystallization temperature. This creates the conditions for spontaneous formation of microcrystallites at the wire edge and the movement of the crystal–amorphous interface along the wire. It was found that the directed crystallization is possible in a narrow temperature interval of 5–7° near the crystallization temperature. The effect of the directed crystallization on the magnetic properties is evident from a giant increase in coercivity, up to 1000 times. The directed crystallization was also assisted by application of a magnetic field which resulted in greater increase in coercivity, up to 1500 times and the coercivity value reached 69400 A m−1. For comparison, at a standard crystallization the coercivity increases by 8–10 times being in the range of 2000–4000 A m−1. The developed micro‐magnets can find a range of applications in miniature sensors, actuators, and manipulators.
On the different origins of electrical parameter degradation in reverse‐bias stressed AlGaN/GaN HEMTs
Authors: Ghosh Saptarsi , Dinara Syed M. , Mahata Mihir , Das Subhashis , Mukhopadhyay Partha , Jana Sanjay Kumar , Biswas Dhrubes
Published: February 2016

Reverse bias stressing in AlGaN/GaN high electron mobility transistors (HEMTs) compelled severe degradation of drain current (IDS) whereas gate current (IG) remained largely unaffected. Besides, the response of access region conductivity to pulse drives was found to deteriorate gradually as a result of stress, and an interacting deep level in the form of kink effect was observed. Post degradation, SEM imaging evidenced the field‐induced formation of protruding particles, immediately adjacent to the gate electrode. Auger spectroscopy and elemental mapping chemically identified these insulating particles as gallium oxide. Barrier/channel consumption in the form of electrochemical oxidation is thus held responsible for IDS degradation whereas IG degradation is entirely attributed on the presence of passivation layer.

SEM micrographs of the (a) tested, and (b) untested finger of a −80 V bias stressed HEMT. (c) Auger spectra from an insulating particle, whereas (d) and (e) are oxygen and gallium elemental maps of the entire frame (c).
Structural and optical properties of CdTe thin film: A detailed investigation using optical absorption, XRD, and Raman spectroscopies
Authors: Nassar Zaher Mahmoud , Yükselici Mehmet Hikmet , Bozkurt Asuman Aşıkoğlu
Published: February 2016

Physical vapor deposition (PVD) is used to grow CdTe thin films of different thicknesses on glass substrates. The characterization of the samples is then investigated optically and structurally. Three experimental techniques were used in this study; optical absorption (ABS), Raman, and X‐ray diffraction (XRD) spectroscopies. In optical ABS spectroscopy, the Urbach energy related to the width of long‐wavelength tail decreases from 827 to 585 meV as the thickness increases from 100 to 500 nm, respectively. The thickness‐dependent particle size was calculated using the value of the size‐dependent optical absorption edge energy. A shift of 710 meV in the ABS edge energy takes place as the thickness increases from 100 to 500 nm. Thickness‐dependent shifting and widening of XRD line is presumably due to the size effect and strain. Relative to the phonon frequency of bulk CdTe crystal, a thickness‐dependent blueshift was observed in Raman spectra for the Longitudinal Optical (LO) phonon frequency, while a redshift for the longitudinal acoustic (LA) and transverse optical (TO) phonon frequencies is observed. In the present work, the results of optical absorption, XRD, and Raman analyses are combined in order to study the effect of particle‐size evolution, thickness‐dependent strain, and structural disorder.
Modulating optical second harmonic generation of impurity‐doped quantum dots in presence of Gaussian white noise
Authors: Ganguly Jayanta , Ghosh Manas
Published: February 2016

We perform an exhaustive exploration of profiles of second harmonic generation (SHG) coefficient of impurity‐doped quantum dots (QDs) in presence and absence of noise. The quantum dot is doped with Gaussian impurity. Noise has been applied to the system additively and multiplicatively. A perpendicular magnetic field emerges out as a confinement source and a static external electric field has been applied. The SHG profiles have been pursued as a function of incident photon energy when several important parameters such as electric field strength, magnetic field strength, confinement energy, dopant location,Alconcentration, dopant potential, and noise strength assume different values. Moreover, the role of mode of application of noise (additive/multiplicative) on the SHG profiles has also been critically analyzed. The SHG profiles are found to be enriched with interesting observations such asshift of SHG peak positionandmaximization/minimization of SHG peak intensity. Presence of noise alters the features of SHG profiles through some interesting outcomes. Furthermore, the mode of application of noise (additive/multiplicative) also regulates the SHG profiles in diverse as well as often contrasting manners. The observations highlight the possibilities of tuning the SHG coefficient of doped QD systems in presence of noise.
MOCVD growth of ZnO nanowires on Ni–W metallic substrates
Authors: Amiri Gaëlle , Halaoui Mohamed , Montenegro Diana Nathalie , Galtier Pierre , Sallet Vincent
Published: February 2016

Here we investigate the possibility to grow ZnO nanowires on (100) textured Ni‐W substrates by MOCVD at 850 °C. Due to the oxidation of Ni, direct growth of ZnO nanowires on those metallic substrates was not achieved whereas it was easily obtained on sapphire in the same conditions. Therefore, a study of a ZnO buffer layer grown at low temperature was performed in order to prevent the NiO formation. The morphology and the crystallographic orientation of the as‐grown interfacial layers were characterized by scanning emission microscopy (SEM) and XRD diffraction, and are shown to depend on the growth temperature. Subsequently, the growth of ZnO nanowires was carried out on ZnO buffer/Ni‐W pseudo‐substrates. The SEM observations reveal the growth is not homogeneous and depends on the grain orientation. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Total robotic radical rectal resection with da Vinci Xi system: single docking, single phase technique
Authors: Tamhankar Anup Sunil , Jatal Sudhir , Saklani Avanish
Published: February 2016

Objective

This study aims to assess the advantages of Da Vinci Xi system in rectal cancer surgery. It also assesses the initial oncological outcomes after rectal resection with this system from a tertiary cancer center in India.

Introduction

Robotic rectal surgery has distinct advantages over laparoscopy. Total robotic resection is increasing following the evolution of hybrid technology. The latest Da Vinci Xi system (Intuitive Surgical, Sunnyvale, USA) is enabled with newer features to make total robotic resection possible with single docking and single phase.

Methods and results

Thirty‐six patients underwent total robotic resection in a single phase and single docking. We used newer port positions in a straight line. Median distance from the anal verge was 4.5 cm. Median robotic docking time and robotic procedure time were 9 and 280 min, respectively. Median blood loss was 100 mL. One patient needed conversion to an open approach due to advanced disease. Circumferential resection margin and longitudinal resection margins were uninvolved in all other patients. Median lymph node yield was 10. Median post‐operative stay was 7 days. There were no intra‐operative adverse events.

Conclusion

The latest Da Vinci Xi system has made total robotic rectal surgery feasible in single docking and single phase. With the new system, four arm total robotic rectal surgery may replace the hybrid technique of laparoscopic and robotic surgery for rectal malignancies. The learning curve for the new system appears to be shorter than anticipated. Early perioperative and oncological outcomes of total robotic rectal surgery with the new system are promising. Copyright © 2016 John Wiley & Sons, Ltd.
Improving Representational Competence with Concrete Models
Authors: STIEFF MIKE , SCOPELITIS STEPHANIE , LIRA MATTHEW E. , DESUTTER DANE
Published: February 2016

Representational competence is a primary contributor to student learning in science, technology, engineering, and math (STEM) disciplines and an optimal target for instruction at all educational levels. We describe the design and implementation of a learning activity that uses concrete models to improve students’ representational competence and achievement in an undergraduate chemistry course. In the study, we embedded modeling workshops into the normal course of instruction and measured their effectiveness for improving representational competence. The results indicate that, independent of instructor, the learning activity significantly improved students’ ability to identify spatial information in disciplinary diagrams and translate among molecular representations compared to students who did not complete the activity. We also compared the effectiveness of the modeling workshops to improve achievement on summative course assessments. Despite demonstrated improvement in representational competence, students who received the intervention did not perform significantly better than a control group on course assessments. Finally, we surveyed students who completed the workshops to investigate their beliefs about the utility of concrete models for learning chemistry. Students reported that concrete models are useful for a limited range of tasks. We argue that concrete models offer specific advantages to the student that may help improve representational competence, although such improvement may not generalize.
Color images steganalysis using rgb channel geometric transformation measures
Authors: Abdulrahman Hasan , Chaumont Marc , Montesinos Philippe , Magnier Baptiste
Published: February 2016

In recent years, information security has received a great deal of attention. To give an example, steganography techniques are used to communicate in a secret and invisible way. Digital color images have become a good medium for digital steganography because of their easy manipulation as carriers via Internet, e‐mails, or used on websites. The main goal of steganalysis is to detect the presence of hidden messages in a digital media. The proposed method is a further extension of the authors' previous work: steganalysis based on color feature correlation and machine learning classification. Fusing features with those obtained from color‐rich models allows increasing the detectability of hidden messages in the color images. Our new proposition uses two types of features, computed between color image channels. The first type of feature reflects local Euclidean transformations, and the second one reflects mirror transformations. These geometric measures are obtained by the sine and cosine of gradient angles between all the color channels. Features are extracted from co‐occurrence correlation matrices of measures. We demonstrate the efficiency of the proposed framework on three steganography algorithms designed to hide messages in images represented in the spatial domain: S‐UNIWARD, WOW, and Synch‐HILL. For each algorithm, we applied a range of different payload sizes. The efficiency of the proposed method is demonstrated by the comparison with the previous authors work and the spatial color‐rich model and color filter array‐aware features for steganalysis. Copyright © 2016 John Wiley & Sons, Ltd.
The use of asymmetric distributions in average bioequivalence
Authors: de Souza Roberto Molina , Achcar Jorge Alberto , Martinez Edson Zangiacomi , Mazucheli Josmar
Published: February 2016

Generic drugs have been commercialized in numerous countries. Most of these countries approve the commercialization of a generic drug when there is evidence of bioequivalence between the generic drug and the reference drug. Generally, the pharmaceutical industry is responsible for the bioequivalence test under the supervision of a regulatory agency. This procedure is concluded after a statistical data analysis. Several agencies adopt a standard statistical analysis based on procedures that were previously established. In practice, we face situations in which this standard model does not fit to some sets of bioequivalence data. In this study, we propose an evaluation of bioequivalence using univariate and bivariate models based on an extended generalized gamma distribution and a skew‐t distribution, under a Bayesian perspective. We introduce a study of the empirical power of hypothesis tests for univariate models, showing advantages in the use of an extended generalized gamma distribution. Three sets of bioequivalence data were analyzed under these new procedures and compared with the standard model proposed by the majority of regulatory agencies. In order to verify that the asymmetrical distributions are usually better fitted for the data, when compared with the standard model, model discrimination methods were used, such as the Deviance Information Criterion (DIC) and quantile–quantile plots. The research concluded that, in general, the use of the extended generalized gamma distribution may be more appropriate to model bioequivalence data in the original scale. Copyright © 2016 John Wiley & Sons, Ltd.
Concise Review: Progress and Challenges in Using Human Stem Cells for Biological and Therapeutics Discovery: Neuropsychiatric Disorders
Authors: Panchision David M.
Published: February 2016

In facing the daunting challenge of using human embryonic and induced pluripotent stem cells to study complex neural circuit disorders such as schizophrenia, mood and anxiety disorders, and autism spectrum disorders, a 2012 National Institute of Mental Health workshop produced a set of recommendations to advance basic research and engage industry in cell-based studies of neuropsychiatric disorders. This review describes progress in meeting these recommendations, including the development of novel tools, strides in recapitulating relevant cell and tissue types, insights into the genetic basis of these disorders that permit integration of risk-associated gene regulatory networks with cell/circuit phenotypes, and promising findings of patient-control differences using cell-based assays. However, numerous challenges are still being addressed, requiring further technological development, approaches to resolve disease heterogeneity, and collaborative structures for investigators of different disciplines. Additionally, since data obtained so far is on small sample sizes, replication in larger sample sets is needed. A number of individual success stories point to a path forward in developing assays to translate discovery science to therapeutics development.
Response of North Pacific eastern subtropical mode water to greenhouse gas versus aerosol forcing
Authors: Li Xiang , Luo Yiyong
Published: February 2016

Mode water is a distinct water mass characterized by a near vertical homogeneous layer or low potential vorticity, and is considered essential for understanding ocean climate variability. Based on the output of GFDL CM3, this study investigates the response of eastern subtropical mode water (ESTMW) in the North Pacific to two different single forcings: greenhouse gases (GHGs) and aerosol. Under GHG forcing, ESTMW is produced on lighter isopycnal surfaces and is decreased in volume. Under aerosol forcing, in sharp contrast, it is produced on denser isopycnal surfaces and is increased in volume. The main reason for the opposite response is because surface ocean-to-atmosphere latent heat flux change over the ESTMW formation region shoals the mixed layer and thus weakens the lateral induction under GHG forcing, but deepens the mixed layer and thus strengthens the lateral induction under aerosol forcing. In addition, local wind changes are also favorable to the opposite response of ESTMW production to GHG versus aerosol.
Evaluation of Disaster Preparedness Based on Simulation Exercises: A Comparison of Two Models
Authors: Rüter Andres , Kurland Lisa , Gryth Dan , Murphy Jason , Rådestad Monica , Djalali Ahmadreza
Published: February 2016

Objective

The objective of this study was to highlight 2 models, the Hospital Incident Command System (HICS) and the Disaster Management Indicator model (DiMI), for evaluating the in-hospital management of a disaster situation through simulation exercises.

Methods

Two disaster exercises, A and B, with similar scenarios were performed. Both exercises were evaluated with regard to actions, processes, and structures. After the exercises, the results were calculated and compared.

Results

In exercise A the HICS model indicated that 32% of the required positions for the immediate phase were taken under consideration with an average performance of 70%. For exercise B, the corresponding scores were 42% and 68%, respectively. According to the DiMI model, the results for exercise A were a score of 68% for management processes and 63% for management structure (staff skills). In B the results were 77% and 86%, respectively.

Conclusions

Both models demonstrated acceptable results in relation to previous studies. More research in this area is needed to validate which of these methods best evaluates disaster preparedness based on simulation exercises or whether the methods are complementary and should therefore be used together. (Disaster Med Public Health Preparedness. 2016;10:544–548).
A technique to predict the aerodynamic effects of battle damage on an aircraft’s wing
Authors: Pickhaver T.W. , Render P.M.
Published: February 2016

A technique is developed that can be used to predict the effects of battle damage on the aerodynamic performance of an aircraft’s wing. The technique is based on results obtained from wind tunnel tests on a NASA LS(1)-0417MOD aerofoil with simulated gunfire damage. The wind tunnel model incorporated an internal cavity to represent typical aircraft construction and this was located between 24% and 75% of chord. The damage was simulated by circular holes with diameters between 20% and 40% of chord. To represent different attack directions, the inclination of the hole axis relative to the aerofoil chord was varied between ±60° pitch and 45° of roll. The aerofoil spanned the wind tunnel to create approximate two-dimensional conditions and balance measurements were carried out at a Reynolds number of 500,000 for incidences, increased in 2° increments, from –4° to 16°. Surface flow visualisation and pressure measurements were also carried out. For a given hole size, the increments in lift, drag and pitching moment coefficients produced trends when plotted against the difference between the upper and lower surface pressure coefficients on the undamaged aerofoil taken at the location of the damage. These trends are used as the basis of the predictive technique. The technique is used to predict the effects of a previously untested damage case, and these are compared with wind tunnel tests carried out on a half model finite aspect ratio wing. For all coefficients the trends in the predicted data are similar to experiment, although there are some discrepancies in absolute values. For the drag coefficient these discrepancies are partly accounted for by limitations in the technique, whilst discrepancies in the lift and pitching moment coefficients are attributed to limitations in the aerofoil test arrangements.
Static aeroelastic optimisation to wing structural weight estimation of an extremely manoeuvrable UAV
Authors: Yi L. , Jun Y. , Bin K.
Published: February 2016

Estimating the wing structural weight of an extremely manoeuvrable Unmanned Aerial Vehicle (UAV) during conceptual design has proven to be a significant challenge due to its high load factor (the ratio of an aircraft lift to its weight). The traditional empirical method relies on existing statistical data of previously built aircraft, then is inadequate for the innovative UAV structure design which can endure extremely manoeuvrable load (load factor is greater than 9g). In this paper, the finite element model for wing structure of an extremely manoeuvrable UAV with foreplane was built, and the structural weight was estimated by static aeroelastic optimisation considering structural strength and buckling constraints. The methodology developed here is only consisted of three components, which is much less than that for existing method, thus the procedure developed here sacrificed some accuracy, but it’s faster and more suitable for aircraft conceptual design. It was validated by the overlap between the weights given by the methodology, and the results from empirical equations when the load factors are less than 9g. Through the analysis procedure developed, the wing structural weights of the extremely manoeuvrable UAV were given under different load cases (load factor changes from 5g to 12g).
Effect of wing-box structure on the optimum wing outer shape
Authors: Elham A. , van tooren M. J. L.
Published: February 2016

A new method for wing shape optimisation is presented, in which the wing shape is optimised not only for the best aerodynamic properties but also for minimum structural weight. An advanced structural sizing method for wing structural weight estimation is developed. The method is based on elementary, physics based analyses of simplified structure to determine the amount of required material to resist the applied loads. The sizing loads are determined based on the airworthiness regulations using advanced aerodynamic analysis tools. In this new weight estimation method, the effect of wing outer (aerodynamic) shape on the wing-box structural weight is taken into account. A mathematical equation is derived, which relates the wing-box structural weight to the wing outer shape. The weight estimation method is validated for several existing passenger aircraft. A series of optimisations is performed to optimise the wing shape for a general objective function, which includes both aerodynamic and structural properties of the wing. The aircraft fuel weight is used as the objective function. Different structures are tested both metal and composite ones. The latter includes different composite layups. In order to find the effect of the internal structure on the optimum wing outer shape, the design lift coefficient is assumed to be constant for all the test cases. The results of the optimisations showed that the optimum wing shape is depending on the structural concept (metal alloys versus different composite layups) for different internal structures.
Efficient optimisation of large aircraft fuselage structures
Authors: Vankan W. J. , Maas R. , Grihon S.
Published: February 2016

This paper presents an innovative optimisation method for aircraft fuselage structural design. Detailed local finite element analyses of panel buckling are further processed such that they can be applied as failure constraints in the global level optimisation. The high computational costs involved with the finite element analyses are limited by advanced use of surrogate modelling methods. This yields high flexibility and efficiency in the local level optimisation procedure and allows for efficient gradient based search methods as well as more costly direct search optimisations like genetic algorithms (GAs). The method is demonstrated on a composite fuselage barrel design case considering common structural sizing variables like thicknesses and stringer dimensions. Optimised barrel designs are obtained where the constraints that are derived from the panel buckling analyses are active. The total computational cost for the complete local and global level optimisation procedures is in the order of days on common-performance hardware.
On power and actuation requirement in swashplateless primary control of helicopters using trailing-edge flaps
Authors: Gandhi F. , Duling C. , Straub F.
Published: February 2016

This paper examines three specific aspects pertaining to the trailing-edge flap (TEF) enabled swashplateless primary control of a helicopter. The study is based on a utility helicopter very similar to the UH-60A Blackhawk helicopter, with rotor torsion frequency reduced to 2·1/rev, and 20% chord TEFs extending from 70-90% span. The questions addressed in the paper are the power penalty due to aerodynamic drag associated with TEF control, the pitch-index required to limit the range of TEF deflections over variations in aircraft gross-weight and airspeed, and the influence of rotor RPM variation on swashplateless primary control. Results indicate that the power penalty associated with TEF enabled primary control at high speeds is in the range of 6-7%, due to increased drag on the advancing side in the region of the TEFs and at the blade tips. At low to moderate speeds the increase in power is 2-4% on average, more dependent on the pitch-index, and due to drag increase over most of the azimuth in the region of the TEFs. A variation in pitch-index from 16° for lower speeds and gross weights, to 20-22° for higher speeds and gross weights, would reduce the steady level flight TEF defection requirements to under ±3°, leaving sufficient control margin. Increase in rotor RPM does not increase directly increase thrust (as with a stiff-torsion rotor) but reduces the rotating torsion frequency, and together with the increased dynamic pressures increases the sensitivity to TEF control. At low to moderate speeds a 9% increase in RPM reduces the maximum TEF deflections required by about 1°, but is accompanied by a large increase in rotor power. Conversely, a 9% RPM reduction decreases rotor power required, but the TEF defections required increase by 1–1·5°.
The PBP Bow-Tie framework for the systematic representation and comparison of military aviation regulatory frameworks
Authors: Purton L. , Clothier R. , Kourousis K. , Massey K.
Published: February 2016

This paper presents a novel framework, based on traditional system safety modelling approaches, for the representation and comparison of airworthiness aviation frameworks. A disparate array of military airworthiness frameworks have emerged due to a lack of standardisation and the absence of a recognised organisation needed for the harmonisation of military regulatory frameworks.. The complexity and subsequent cost in inter-agency recognition of existing certification programs has led to the establishment of a European forum of military airworthiness authorities. The forum is working towards establishing a common regulatory framework across its European member states. The common framework provides the systematic basis for a certification of military aircraft that can be readily recognised by all of the member states. This will have many cost and efficiency benefits for the EU. The framework and recognition process have recently been accepted as a method for establishing recognition outside of Europe, with some identified shortfalls. This paper establishes a method for overcoming these shortfalls for nations outside of europe. The Product-Behaviour-Process (PBP) Bow-Tie, which is a novel application of the traditional bowtie risk modelling tool, derives test points that capture the airworthiness attestations for the high-level engineering lifecycle processes of design, production and maintenance. The proposed framework is used to provide a comparison between the Australian Defence Force and United States Army regulatory frameworks. The comparative case-study clearly demonstrates the benefit of the PBP Bow-Tie model in its ability to systematically represent the disparate regulatory frameworks. A novel representation of the output is also described, which facilitates a visual comparison of the results. The application of the PBP Bow-Tie framework to the case-study of regulatory frameworks reveals significant differences that need to be addressed in order for inter-agency recognition.
Strategic forecasting in uncertain environments: hypersonic cruise vehicle research and development case study
Authors: Chudoba B. , Haney E. , Gonzalez L. , Omoragbon A. , Oza A.
Published: February 2016

The exponentially increasing amount of information accumulated from past to current engineering projects has created an environment where repurposing existing data to support new projects is paramount to sustainable success. Strategic planning and early design decisions, specifically, occur in decision-making environments that require information support capabilities that lie outside of traditional engineering analyses. In order to advance towards a more complete planning environment, a pragmatic methodology has been developed for modern aerospace data and information collection, categorisation, and utilisation with a focus on current efforts in hypersonic vehicle research and development. The main thrust has been to provide insights into financial and technical trends that support objective programmatic and planning decision-making. The end-product is a suite of graphical decision-making interfaces, linked through a unified hypersonic database. The graphical interfaces are capable of highlighting the key project drivers along varying levels of categorisation and refinement. Aided by these newly developed data and information support interfaces covering past and present hypersonic efforts, the planner’s forecasting assessment of present and future hypersonic research and development efforts is pragmatically enriched towards a more complete managerial program-planning framework.
Design of a quadrotor flight test stand for system identification
Authors: Beharie M. M. , Pedro J. O. , Dala L.
Published: February 2016

This paper presents the design, development and construction of a flight test stand for a quadrotor UAV. As opposed to alternate forms of UAV, the power plant in the case of the quadrotor serves a dual purpose of control and propulsion. Since control and propulsion are coupled, the power plant (BLDC motor coupled with propeller) was studied in detail using a black box structure. Extractions of motor parameters in previous studies used traditional BLDC motor equations and propeller theory however the accuracy achievable and confidence in the extracted parameters remained questionable. The developed data acquisition process served to satisfy this need by the construction of a test bench that allows for the extraction of the unknown parameters instilling confidence in the modelling process. The established relationships are then used as inputs into a developed six degree of freedom Euler based mathematical model. A mission profile was constructed with distinct phases of which the mathematical model was used to simulate. Each phase in the mission profile excited different modes of the quadrotor dynamics creating an ideal simulation environment in which changes can be implemented and studied.
Design, numerical simulation and experimental testing of a controlled electrical actuation system in a real aircraft morphing wing model
Authors: Botez R. M. , Kammegne M. J. Tchatchueng , Grigorie L. T.
Published: February 2016

The paper focuses on the modelling, simulation and control of an electrical miniature actuator integrated in the actuation mechanism of a new morphing wing application. The morphed wing is a portion of an existing regional aircraft wing, its interior consisting of spars, stringers, and ribs, and having a structural rigidity similar to the rigidity of a real aircraft. The upper surface of the wing is a flexible skin, made of composite materials, and optimised in order to fulfill the morphing wing project requirements. In addition, a controllable rigid aileron is attached on the wing. The established architecture of the actuation mechanism uses four similar miniature actuators fixed inside the wing and actuating directly the flexible upper surface of the wing. The actuator was designed in-house, as there is no actuator on the market that could fit directly inside our morphing wing model. It consists of a brushless direct current (BLDC) motor with a gearbox and a screw for pushing and pulling the flexible upper surface of the wing. The electrical motor and the screw are coupled through a gearing system. Before proceeding with the modelling, the actuator is tested experimentally (stand alone configuration) to ensure that the entire range of the requirements (rated or nominal torque, nominal current, nominal speed, static force, size) would be fulfilled. In order to validate the theoretical, simulation and standalone configuration experimental studies, a bench testing and a wind-tunnel testing of four similar actuators integrated on the real morphing wing model are performed.
Aerodynamic shape optimisation of a proprotor and its validation by means of CFD and experiments
Authors: Droandi G. , Gibertini G.
Published: February 2016

The aerodynamic shape design of a proprotor for a tiltrotor aircraft is a very complex and demanding task because it has to combine good hovering capabilities with high propeller efficiency. The aim of the present work is to describe a two-level procedure and its results for the aerodynamic shape design of a new rotor blade for a high-performance tiltwing tiltrotor aircraft taking into account the most important flight conditions in which the aircraft can operate. Span-wise distributions of twist, chord and aerofoil were chosen making use of a multi-objective genetic optimiser that worked on three objectives simultaneously. A non-linear sweep angle distribution along the blade was designed to reduce the power losses due to compressibility effects during axial flight at high speed. During the optimisation process, the aerodynamic performance of the blade was evaluated with a classical two-dimensional strip theory solver. The optimised blade was than analysed by means of a compressible Navier-Stokes solver and calculations were validated comparing numerical results with experimental data obtained from wind-tunnel tests of a scaled model of the proprotor.
Experimental investigation of an active twist model rotor blade with a low voltage actuation system
Authors: Wierach P. , Opitz S. , Kalow S.
Published: February 2016

Smart materials that are directly embedded in the rotor blade structure are an attractive concept for active blade control. A promising approach is the use of anisotropic piezoelectric strain actuators embedded in the rotor blade skin. Especially in Europe and the US this concept has been intensively investigated over the past years. A major drawback of all configurations studied so far is the high operation voltage of up to 2,000V of state of the art piezoelectric actuators. Within the Green Rotorcraft Project of the European Joint Technology Initiative Clean Sky, a new approach with a low voltage piezoelectric actuation system is investigated to demonstrate the feasibility of this technology.

A first major step in this direction was completed by conducting a centrifugal test with a model rotor blade. The objective of the centrifugal test was to demonstrate the performance of the actuation system and the structural concept under centrifugal loads by showing that the expected twist deformation can be achieved at the nominal rotation speed and different actuation frequencies.

It was demonstrated that the new actuation system is capable of operating under representative centrifugal loads. In comparison to state-of-the-art actuators (operation voltage 500V to +1500V) the new actuation system (operation voltage -20V to 120V) exhibits higher active twist performance per active area.
Reproducibility of resting metabolic rate measurement in children
Authors: Ventham Jonathan C. , Reilly John J.
Published: February 2016

The aim of the present study was to determine the reproducibility of measurement of resting metabolic rate (RMR) using a ventilated-hood indirect calorimeter in children using a short protocol suitable for the outpatient setting or home visit. The protocol consisted of an overnight (10–12 h) fast, 5–10 min supine rest, 5–10 min ‘settling in’ under the ventilated hood, and 12–16 min of measurement. Three measurements of RMR were made in eighteen healthy children (nine boys, nine girls, aged 6–11 years) on alternate days. Reproducibility of RMR was assessed using a reproducibility index and by calculating the CV for intra-individual measurements. The mean CV was 2·6 (sd 1·7)% and the reproducibility index was 95·0 %, indicating excellent reliability. The short protocol had higher reproducibility than more stringent protocols described in the literature. The new protocol has a number of practical advantages and should be adequate for most clinical or research purposes.
Payday lending in the UK: the regul(aris)ation of a necessary evil?
Authors: ROWLINGSON KAREN , APPLEYARD LINDSEY , GARDNER JODI
Published: February 2016

Concern about the increasing use of payday lending led the UK's Financial Conduct Authority to introduce landmark reforms in 2014/15. While these reforms have generally been welcomed as a way of curbing ‘extortionate’ and ‘predatory’ lending, this paper presents a more nuanced picture based on a theoretically-informed analysis of the growth and nature of payday lending combined with original and rigorous qualitative interviews with customers. We argue that payday lending has grown as a result of three major and inter-related trends: growing income insecurity for people both in and out of work; cuts in state welfare provision; and increasing financialisation. Recent reforms of payday lending do nothing to tackle these root causes. Our research also makes a major contribution to debates about the ‘everyday life’ of financialisation by focusing on the ‘lived experience’ of borrowers. We show that, contrary to the rather simplistic picture presented by the media and many campaigners, various aspects of payday lending are actually welcomed by customers, given the situations they are in. Tighter regulation may therefore have negative consequences for some. More generally, we argue that the regul(aris)ation of payday lending reinforces the shift in the role of the state from provider/redistributor to regulator/enabler.
The complex mosaic of Englishes
Authors: Rajagopalan K.
Published: February 2016

The English language is no longer any one nation's monopoly; practically every nation on earth has a stake in it. This is the overall thrust of the book in the spotlight. The amazing journey of the language from a none-too-conspicuous dialect once spoken on a part of a tiny island off the north-western coast of Continental Europe to a language of wider communication across the world is the topic that the book engages with. In the ten chapters that make up this book, Urszula Clark surveys the current state of the language in its worldwide spread, along with the inevitable phenomenon of the emergence of new regional varieties or ‘Englishes’.
UNDERSTANDING VARIATIONS IN RELATIVE EFFECTIVENESS: A HEALTH PRODUCTION APPROACH
Authors: Towse Adrian , Jonsson Bengt , McGrath Clare , Mason Anne , Puig-Peiro Ruth , Mestre-Ferrandiz Jorge , Pistollato Michele , Devlin Nancy
Published: February 2016

Background: Relative effectiveness has become a key concern of health policy. In Europe, this is because of the need for early information to guide reimbursement and funding decisions about new medical technologies. However, ways that effectiveness (does it work?) and efficacy (can it work?) might differ across health systems are poorly understood.

Methods: This study proposes an analytical framework, drawing on production function theory, to systematically identify and quantify the determinants of relative effectiveness and sources of variation between populations and healthcare systems. We consider how methods such as stochastic frontier analysis and data envelopment analysis using a Malmquist productivity index could in principle be used to generate evidence on, and improve understanding about, the sources of variation in relative effectiveness between countries and over time.

Results: Better evidence on factors driving relative effectiveness could: inform decisions on how to best use a new technology to maximum effectiveness; establish the need if any for follow-up post-launch studies, and provide evidence of the impact of new health technologies on outcomes in different healthcare systems.

Conclusions: The health production function approach for assessment of relative effectiveness is complementary to traditional experimental and observational studies, focusing on identifying, collecting, and analyzing data at the national level, enabling comparisons to take place. There is a strong case for exploring the use of this approach to better understand the impact of new medicines and devices for improvements in health outcomes.
Exposure to viral and bacterial pathogens among Soay sheep (Ovis aries) of the St Kilda archipelago
Authors: GRAHAM A. L. , NUSSEY D. H. , LLOYD-SMITH J. O. , LONGBOTTOM D. , MALEY M. , PEMBERTON J. M. , PILKINGTON J. G. , PRAGER K. C. , SMITH L. , WATT K. A. , WILSON K. , McNEILLY T. N. , BRÜLISAUER F.
Published: February 2016

We assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure toLeptospiraspp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor toChlamydia abortus. Some sheep tested positive for antibodies againstMycobacterium aviumsubsp.paratuberculosis(MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen–host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.
Visualizing Cross-Sectional Data in a Real-World Context
Authors: Van Noten Koen
Published: February 2016

Combining the capabilities of an open-source drawing tool with Google Earth™ maps allows researchers to visualize real-world cross-sectional data in three dimensions.
Satellites Test Theory of Magnetic Reconnection
Authors: Zastrow Mark
Published: February 2016

A quartet of satellites flying through Earth's magnetic field measures its interaction with the Sun's and puts a theory about their reconnection to the test.
Constitutive p53 heightens mitochondrial apoptotic priming and favors cell death induction by BH3 mimetic inhibitors of BCL-xL
Authors: Le Pen J , Laurent M , Sarosiek K , Vuillier C , Gautier F , Montessuit S , Martinou J C , Letaï A , Braun F , Juin P P
Published: February 2016

Proapoptotic molecules directly targeting the BCL-2 family network are promising anticancer therapeutics, but an understanding of the cellular stress signals that render them effective is still elusive. We show here that the tumor suppressor p53, at least in part by transcription independent mechanisms, contributes to cell death induction and full activation of BAX by BH3 mimetic inhibitors of BCL-xL. In addition to mildly facilitating the ability of compounds to derepress BAX from BCL-xL, p53 also provides a death signal downstream of anti-apoptotic proteins inhibition. This death signal cooperates with BH3-induced activation of BAX and it is independent from PUMA, as enhanced p53 can substitute for PUMA to promote BAX activation in response to BH3 mimetics. The acute sensitivity of mitochondrial priming to p53 revealed here is likely to be critical for the clinical use of BH3 mimetics.
Humans and seasonal climate variability threaten large-bodied coral reef fish with small ranges
Authors: Mellin C. , Mouillot D. , Kulbicki M. , McClanahan T. R. , Vigliola L. , Bradshaw C. J. A. , Brainard R. E. , Chabanet P. , Edgar G. J. , Fordham D. A. , Friedlander A. M. , Parravicini V. , Sequeira A. M. M. , Stuart-Smith R. D. , Wantiez L. , Caley M. J.
Published: February 2016

Coral reefs are among the most species-rich and threatened ecosystems on Earth, yet the extent to which human stressors determine species occurrences, compared with biogeography or environmental conditions, remains largely unknown. With ever-increasing human-mediated disturbances on these ecosystems, an important question is not only how many species can inhabit local communities, but also which biological traits determine species that can persist (or not) above particular disturbance thresholds. Here we show that human pressure and seasonal climate variability are disproportionately and negatively associated with the occurrence of large-bodied and geographically small-ranging fishes within local coral reef communities. These species are 67% less likely to occur where human impact and temperature seasonality exceed critical thresholds, such as in the marine biodiversity hotspot: the Coral Triangle. Our results identify the most sensitive species and critical thresholds of human and climatic stressors, providing opportunity for targeted conservation intervention to prevent local extinctions.
Marine mammals harbor unique microbiotas shaped by and yet distinct from the sea
Authors: Bik Elisabeth M. , Costello Elizabeth K. , Switzer Alexandra D. , Callahan Benjamin J. , Holmes Susan P. , Wells Randall S. , Carlin Kevin P. , Jensen Eric D. , Venn-Watson Stephanie , Relman David A.
Published: February 2016

Marine mammals play crucial ecological roles in the oceans, but little is known about their microbiotas. Here we study the bacterial communities in 337 samples from 5 body sites in 48 healthy dolphins and 18 healthy sea lions, as well as those of adjacent seawater and other hosts. The bacterial taxonomic compositions are distinct from those of other mammals, dietary fish and seawater, are highly diverse and vary according to body site and host species. Dolphins harbour 30 bacterial phyla, with 25 of them in the mouth, several abundant but poorly characterized Tenericutes species in gastric fluid and a surprisingly paucity of Bacteroidetes in distal gut. About 70% of near-full length bacterial 16S ribosomal RNA sequences from dolphins are unique. Host habitat, diet and phylogeny all contribute to variation in marine mammal distal gut microbiota composition. Our findings help elucidate the factors structuring marine mammal microbiotas and may enhance monitoring of marine mammal health.