bluuebunny/crossref_metadata_2025 huggingface dataset:
Promoting mobility and reducing length of stay in hospitalized general medicine patients: A quality‐improvement project
Authors: Hoyer Erik H. , Friedman Michael , Lavezza Annette , Wagner‐Kosmakos Kathleen , Lewis‐Cherry Robin , Skolnik Judy L. , Byers Sherrie P. , Atanelov Levan , Colantuoni Elizabeth , Brotman Daniel J. , Needham Dale M.
Published: February 2016

OBJECTIVE

To determine whether a multidisciplinary mobility promotion quality‐improvement (QI) project would increase patient mobility and reduce hospital length of stay (LOS).

PATIENTS AND METHODS

Implemented using a structured QI model, the project took place between March 1, 2013 and March 1, 2014 on 2 general medicine units in a large academic medical center. There were 3352 patients admitted during the QI project period. The Johns Hopkins Highest Level of Mobility (JH‐HLM) scale, an 8‐point ordinal scale ranging from bed rest (score = 1) to ambulating ≥250 feet (score = 8), was used to quantify mobility. Changes in JH‐HLM scores were compared for the first 4 months of the project (ramp‐up phase) versus 4 months after project completion (post‐QI phase) using generalized estimating equations. We compared the relative change in median LOS for the project months versus 12 months prior among the QI units, using multivariable linear regression analysis adjusting for 7 demographic and clinically relevant variables.

RESULTS

Comparing the ramp‐up versus post‐QI phases, patients reaching JH‐HLM's ambulation status increased from 43% to 70% (P < 0.001), and patients with improved JH‐HLM mobility scores between admission and discharge increased from 32% to 45% (P < 0.001). For all patients, the QI project was associated with an adjusted median LOS reduction of 0.40 (95% confidence interval [CI]: −0.57 to −0.21, P < 0.001) days compared to 12 months prior. A subgroup of patients expected to have a longer LOS (expected LOS >7 days), were associated with a significantly greater adjusted median reduction in LOS of 1.11 (95% CI: −1.53 to −0.65, P < 0.001) days. Increased mobility was not associated with an increase in injurious falls compared to 12 months prior on the QI units (P = 0.73).

CONCLUSIONS AND RELEVANCE

Active prevention of a decline in physical function that commonly occurs during hospitalization may be achieved with a structured QI approach. In an adult medicine population, our QI project was associated with improved mobility, and this may have contributed to a reduction in LOS, particularly for more complex patients with longer expected hospital stay. Journal of Hospital Medicine 2016. © 2016 Society of Hospital Medicine
Spectroscopic and microcalorimetric studies on the molecular binding of food colorant acid red 27 with deoxyribonucleic acid
Authors: Basu Anirban , Kumar Gopinatha Suresh
Published: February 2016

Interaction of the food colorant acid red 27 with double stranded DNA was investigated using spectroscopic and calorimetric methods. Absorbance and fluorescence studies suggested an intimate binding interaction between the dye and DNA. The quantum efficiency value testified an effective energy transfer from the DNA base pairs to the dye molecules. Minor groove displacement assay with Hoechst 33258 revealed that the binding occurs in the minor groove of DNA. Circular dichroism studies revealed that acid red 27 induces moderate conformational perturbations in DNA. Results of calorimetric studies suggested that the complexation process was driven largely by positive entropic contribution with a smaller favorable enthalpy contribution. The equilibrium constant of the binding was calculated to be (3.04 ± 0.09) × 104 M−1 at 298.15 K. Negative heat capacity value along with the enthalpy–entropy compensation phenomenon established the involvement of dominant hydrophobic forces in the binding process. Differential scanning calorimetry studies presented evidence for an increased thermal stability of DNA on binding of acid red 27. Copyright © 2016 John Wiley & Sons, Ltd.
The Effect of Sterilization Methods on the Structural and Chemical Properties of Fibrin Microthread Scaffolds
Authors: Grasman Jonathan M. , O'Brien Megan P. , Ackerman Kevin , Gagnon Keith A. , Wong Gregory M. , Pins George D.
Published: February 2016

A challenge for the design of scaffolds in tissue engineering is to determine a terminal sterilization method that will retain the structural and biochemical properties of the materials. Since commonly used heat and ionizing energy‐based sterilization methods have been shown to alter the material properties of protein‐based scaffolds, the effects of ethanol and ethylene oxide (EtO) sterilization on the cellular compatibility and the structural, chemical, and mechanical properties of uncrosslinked, UV crosslinked, or 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide (EDC) crosslinked fibrin microthreads in neutral (EDCn) or acidic (EDCa) buffers are evaluated. EtO sterilization significantly reduces the tensile strength of uncrosslinked microthreads. Surface chemistry analyses show that EtO sterilization induces alkylation of EDCa microthreads leading to a significant reduction in myoblast attachment. The material properties of EDCn microthreads do not appear to be affected by the sterilization method. These results significantly enhance the understanding of how sterilization or crosslinking techniques affect the material properties of protein scaffolds.

image
Overconfidence and Disappointment in Decision‐making under Risk: The Triumph of Hope over Experience
Authors: Ringuest Jeffrey L. , Graves Samuel B.
Published: February 2016

Overconfidence in economic decision‐making is a well‐established phenomenon; however, assessment of its scale and impact are largely absent from the literature. This paper uses Bell's disappointment metric to quantify its impact on individual decision‐makers in a risky investment setting. We are able to quantify the sensitivity of disappointment to overconfidence. We examine disappointment in both deterministic and stochastic models, finding that in the most likely cases, individual investors experience lower disappointment when variance is higher. We are also able to quantify and compare calibration‐based overconfidence and better‐than‐average overconfidence. Contrary to prior research, we find that their magnitudes are the same. Copyright © 2016 John Wiley & Sons, Ltd.
Lateral geniculate atrophy in Parkinson's with visual hallucination: A trans‐synaptic degeneration?
Authors: Lee Jee‐Young , Yoon Eun Jin , Lee Woong Woo , Kim Yu Kyeong , Lee Jun‐Young , Jeon Beomseok
Published: February 2016

Introduction

Defective visual information processing contributes to visual hallucination in PD, for which “top‐down” and “bottom‐up” impairment are suggested mechanisms. This study was aimed to investigate macro‐ and microstructural neural changes in afferent visual pathways in relation to visual hallucination in nondemented PD patients.

Methods

This study included 24 nondemented, nondepressed PD patients (10 hallucinating and 14 nonhallucinating) and 15 age‐matched healthy controls. We analyzed volumetric and diffusion tensor MRI data by applying region of interest analyses on the visual pathways, including the optic chiasm, bilateral optic nerves, lateral geniculate bodies, optic radiations, and primary visual cortex.

Results

Patients' demographic characteristics, daily medication doses, as well as duration and motor severity of PD were similar in the two PD groups. Compared to PD patients without hallucination, those with hallucination had fractional anisotropy decrease in the left optic nerve and showed atrophy of lateral geniculate bodies, especially in the left side. In addition, the PD with hallucination group had diffusivity increase in the left optic radiation compared to that in the PD without hallucination and healthy control groups. There were no differences in the primary visual cortex volume among the study groups.

Conclusions

We found microstructural alterations in visual pathways in nondemented PD patients with hallucination, mainly in first‐order neurons and atrophy in the lateral geniculate body where the retinal ganglion cells synapse to second‐order neurons. Afferent visual pathway degeneration may occur in a trans‐synaptic way in PD. Further studies warrant to be conducted. © 2016 International Parkinson and Movement Disorder Society
Pre‐existing differences and diet‐induced alterations in striatal dopamine systems of obesity‐prone rats
Authors: Vollbrecht Peter J. , Mabrouk Omar S. , Nelson Andrew D. , Kennedy Robert T. , Ferrario Carrie R.
Published: February 2016

Objective

Interactions between pre‐existing differences in mesolimbic function and neuroadaptations induced by consumption of fatty, sugary foods are thought to contribute to human obesity. This study examined basal and cocaine‐induced changes in striatal neurotransmitter levels without diet manipulation and D2/D3 dopamine receptor‐mediated transmission prior to and after consumption of “junk‐foods” in obesity‐prone and obesity‐resistant rats.

Methods

Microdialysis and liquid chromatography‐mass spectrometry were used to determine basal and cocaine‐induced changes in neurotransmitter levels in real time with cocaine‐induced locomotor activity. Sensitivity to the D2/D3 dopamine receptor agonist quinpirole was examined before and after restricted junk‐food exposure. Selectively bred obesity‐prone and obesity‐resistant rats were used.

Results

Cocaine‐induced locomotion was greater in obesity‐prone rats versus obesity‐resistant rats prior to diet manipulation. Basal and cocaine‐induced increases in dopamine and serotonin levels did not differ. Obesity‐prone rats were more sensitive to the D2 receptor‐mediated effects of quinpirole, and junk‐food produced modest alterations in quinpirole sensitivity in obesity‐resistant rats.

Conclusions

These data show that mesolimbic systems differ prior to diet manipulation in susceptible versus resistant rats, and that consumption of fatty, sugary foods produce different neuroadaptations in these populations. These differences may contribute to enhanced food craving and an inability to limit food intake in susceptible individuals.
The significance of anterolateral neck cysts in early diagnosis of fetal malformations
Authors: Meyberg‐Solomayer Gabriele , Hamza Amr , Takacs Zoltan , Leingartner Anika , Radosa Julia , Joukhadar Ralf , Juhasz‐Böss Ingolf , Solomayer Erich‐Franz
Published: February 2016

Objective

The objective of this study is to examine the association of lateral fetal neck cysts with increased nuchal translucency, chromosomal abnormalities and fetal malformations.

Method

In a consecutive collective of 4216 prenatal ultrasound examinations between 11 and 17 weeks of gestation 32 fetuses with lateral neck cysts were found. The size of the cysts was examined. The association of the findings with increased nuchal translucency, chromosomal aberrations and fetal malformations was examined.

Results

All but two out of 32 cases had bilateral cysts. Seventeen fetuses had aneuploidy and an increased nuchal translucency, 15 of those with major structural malformations. Of the 15 fetuses with normal karyotype nine (60%) had an increased nuchal translucency, seven had a fetal malformation or hydrops. A favorable outcome was found in 6/15 fetuses with normal karyotype and normal nuchal translucency. Lateral neck cyst diameter was associated to nuchal translucency, chromosomal abnormality and/or fetal malformations. Cysts smaller than 3 mm had a favorable outcome even in the presence of an increased nuchal translucency.

Conclusion

Fetuses with lateral neck cysts often not only present with increased nuchal translucency and chromosomal aberrations but also with fetal malformations. Fetuses with lateral neck cysts and increased nuchal translucency were aneuploid or had a fetal malformation in 85%. Cysts smaller than 3 mm had a favorable outcome. © 2016 John Wiley & Sons, Ltd.
Effectiveness of Pharmacist‐Led Amiodarone Monitoring Services on Improving Adherence to Amiodarone Monitoring Recommendations: A Systematic Review
Authors: Dixon Dave L. , Dunn Steven P. , Kelly Michael S. , McLlarky Timothy R. , Brown Roy E.
Published: February 2016

Amiodarone remains the mostly frequently used antiarrhythmic in clinical practice and is most often used to maintain normal sinus rhythm in patients with atrial fibrillation who have failed a rate control strategy. Amiodarone has superior efficacy over other antiarrhythmics, a lower risk of torsade de pointes, and a better cardiovascular safety profile in patients with structural heart disease. However, amiodarone is associated with notable noncardiac toxicities affecting the thyroid, lungs, eyes, liver, and central nervous system. Since 2000, clinicians have been advised to follow amiodarone monitoring guidelines provided by the Heart Rhythm Society. Adherence to these recommendations in clinical practice, however, is suboptimal. Pharmacists play a major role in ensuring the safe and effective use of medications, particularly high‐risk medications such as amiodarone. This qualitative review details the evidence supporting the role of pharmacist‐led amiodarone monitoring services (AMS) in improving adherence to amiodarone monitoring guidelines and identifying adverse effects. Five studies were identified, and, overall, these programs had a favorable impact on improving adherence to guideline‐recommended monitoring standards for amiodarone. The available evidence is limited by the significant variations in study designs and outcome definitions, lack of patient randomization, and limited generalizability. Nevertheless, available studies suggest that pharmacist‐led AMS may improve adherence to recommended monitoring guidelines and identification of amiodarone‐related adverse effects. Further study is warranted to demonstrate whether these services impact the overall quality of care provided to patients receiving amiodarone, which may justify broader implementation.
Therapeutic Advances in HCV Genotype 1 Infection: Insights from the Society of Infectious Diseases Pharmacists
Authors: Deming Paulina , Martin Michelle T. , Chan Juliana , Dilworth Thomas J. , El‐Lababidi Rania , Love Bryan L. , Mohammad Rima A. , Nguyen Amy , Spooner Linda M. , Wortman Suzanne B.
Published: February 2016

Hepatitis C virus (HCV) is the most common blood‐borne infection in the United States. The high morbidity and mortality due to untreated infection have prompted updated screening recommendations that now include one‐time HCV screening for all patients born between 1945 and 1965, in addition to risk factor–based screening. Current guidelines recommend treatment for all patients with chronic HCV. Treatment for HCV genotype 1 has evolved dramatically since the approval of the direct‐acting antivirals. The approval of ledipasvir‐sofosbuvir, ombitasvir‐paritaprevir‐ritonavir and dasabuvir, and simeprevir with sofosbuvir has dramatically altered the treatment landscape. High sustained virologic response (SVR) rates favor treatment, yet access to care poses a challenge for patients and providers. Current and emerging data with new therapies indicate high SVR rates in treatment‐naïve and treatment‐experienced patients, including patients with cirrhosis and in other special populations. Additional data suggest the addition of ribavirin can decrease treatment duration without compromising SVR rates. Resistance is an increasing area of interest in HCV, with baseline mutations identified and the potential for the development of resistance‐associate variants in patients undergoing treatment. Due to the rapid evolution of HCV treatment, pharmacists should address challenges and play an integral role in agent selection, dosing, drug interaction screening, adverse effect monitoring, and the coordination of treatment. Clinical application of the latest information will reduce patient risk and improve outcomes.
Possible Involvement of Nitric Oxide Modulatory Mechanisms in the Neuroprotective Effect of Centella asiatica Against Sleep Deprivation Induced Anxiety Like Behaviour, Oxidative Damage and Neuroinflammation
Authors: Chanana Priyanka , Kumar Anil
Published: February 2016

Sleep deprivation (SD) is an experience of inadequate or poor quality of sleep that may produce significant alterations in multiple neural systems. Centella asiatica (CA) is a psychoactive medicinal herb with immense therapeutic potential. The present study was designed to explore the possible nitric oxide (NO) modulatory mechanism in the neuroprotective effect of CA against SD induced anxiety like behaviour, oxidative damage and neuroinflammation. Male laca mice were sleep deprived for 72 h, and CA (150 and 300 mg/kg) was administered alone and in combination with NO modulators for 8 days, starting five days before 72‐h SD exposure. Various behavioural (locomotor activity, elevated plus maze) and biochemical (lipid peroxidation, reduced glutathione, catalase, nitrite levels and superoxide dismutase activity), neuroinflammation marker (TNF‐alpha) were assessed subsequently. CA (150 and 300 mg/kg) treatment for 8 days significantly improved locomotor activity, anti‐anxiety like effect and attenuated oxidative damage and TNF α level as compared to sleep‐deprived 72‐h group. Also while the neuroprotective effect of CA was increased by NO antagonists, it was diminished by NO agonists. The present study suggests that NO modulatory mechanism could be involved in the protective effect of CA against SD‐induced anxiety‐like behaviour, oxidative damage and neuroinflammation in mice. Copyright © 2016 John Wiley & Sons, Ltd.
First principles study of O2 dissociation on Pt(111) surface: Stepwise mechanism
Authors: Li Rui , Li Haibo , Liu Jifeng
Published: February 2016

We have performed first‐principle density functional theory calculations to investigate O2 dissociation on Pt(111) surface. A stepwise mechanism has been proposed. First, the adsorbed O2 dissociate into two oxygen atoms to get adsorbed on the nearby adsorption sites. Then, oxygen atoms further migrate to other more stable adsorption sites. The influence of solvent water on oxygen dissociation was also examined. The results show that the co‐adsorption of water has little impact on O2 dissociation. However, when water participates in the reaction, the energy barriers were reduced greatly. These results have very important significance to understand the mechanism of oxygen reduction. © 2016 Wiley Periodicals, Inc.
Understanding the influence of intrinsic and extrinsic factors on inquiry‐based science education at township schools in South Africa
Authors: Ramnarain Umesh
Published: February 2016

This mixed‐methods research investigated teachers' perceptions of intrinsic factors (personal attributes of the teacher) and extrinsic factors (environmental) influencing the implementation of inquiry‐based science learning at township (underdeveloped urban area) high schools in South Africa. Quantitative data were collected by means of an adapted version of the Science Curriculum Implementation Questionnaire (SCIQ) (Lewthwaite, 2001). The adapted version was renamed the Scientific Inquiry Implementation Questionnaire (SIIQ) and was administered to 186 science teachers at township schools in South Africa. The teachers at a township school were then interviewed in order to solicit in‐depth information on the findings that emerged from the questionnaire analysis. The findings highlight a lack of professional science knowledge (content knowledge, pedagogical content knowledge, pedagogical knowledge, knowledge of students, educational contexts, curricular knowledge, and educational purposes) that contributes toward teachers' uncertainty in inquiry‐based teaching. Also, extrinsic factors such as school ethos, professional support, resource adequacy, and time serve as significant constraints in the implementation of inquiry‐based education at the school. The data collected from SIIQ provides a foundation for understanding at a high school level how factors influence the delivery of a curriculum underpinned by inquiry. © 2016 Wiley Periodicals, Inc. J Res Sci Teach 53: 598–619, 2016
Optimal and quasi‐optimal energy‐efficient storage sharing for opportunistic sensor networks
Authors: Kabashi Amar H. , Elmirghani Jaafar M. H.
Published: February 2016

This paper investigates optimum distributed storage techniques for data preservation, and eventual dissemination, in opportunistic heterogeneous wireless sensor networks where data collection is intermittent and exhibits spatio‐temporal randomness. The proposed techniques involve optimally sharing the sensor nodes' storage and properly handling the storage traffic such that the buffering capacity of the network approaches its total storage capacity with minimum energy. The paper develops an integer linear programming (ILP) model, analyses the emergence of storage traffic in the network, provides performance bounds, assesses performance sensitivities and develops quasi‐optimal decentralized heuristics that can reasonably handle the problem in a practical implementation. These include the Closest Availability (CA) and Storage Gradient (SG) heuristics whose performance is shown to be within only 10% and 6% of the dynamic optimum allocation, respectively. Copyright © 2016 John Wiley & Sons, Ltd.
Label‐free detection and manipulation of single biological nanoparticles
Authors: DeSantis Michael C. , Cheng Wei
Published: February 2016

In the past several years, there have been significant advances in the field of nanoparticle detection for various biological applications. Of considerable interest are synthetic nanoparticles being designed as potential drug delivery systems as well as naturally occurring or biological nanoparticles, including viruses and extracellular vesicles. Many infectious diseases and several human cancers are attributed to individual virions. Because these particles likely display different degrees of heterogeneity under normal physiological conditions, characterization of these natural nanoparticles with single‐particle sensitivity is necessary for elucidating information on their basic structure and function as well as revealing novel targets for therapeutic intervention. Additionally, biodefense and point‐of‐care clinical testing demand ultrasensitive detection of viral pathogens particularly with high specificity. Consequently, the ability to perform label‐free virus sensing has motivated the development of multiple electrical‐, mechanical‐, and optical‐based detection techniques, some of which may even have the potential for nanoparticle sorting and multi‐parametric analysis. For each technique, the challenges associated with label‐free detection and measurement sensitivity are discussed as are their potential contributions for future real‐world applications. WIREs Nanomed Nanobiotechnol 2016, 8:717–729. doi: 10.1002/wnan.1392

This article is categorized under:

Diagnostic Tools > In Vitro Nanoparticle-Based Sensing

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease
Study profile: the Durban Diabetes Study (DDS): a platform for chronic disease research
Authors: Hird T. R. , Young E. H. , Pirie F. J. , Riha J. , Esterhuizen T. M. , O'Leary B. , McCarthy M. I. , Sandhu M. S. , Motala A. A.
Published: February 2016

The Durban Diabetes Study (DDS) is a population-based cross-sectional survey of an urban black population in the eThekwini Municipality (city of Durban) in South Africa. The survey combines health, lifestyle and socioeconomic questionnaire data with standardised biophysical measurements, biomarkers for non-communicable and infectious diseases, and genetic data. Data collection for the study is currently underway and the target sample size is 10 000 participants. The DDS has an established infrastructure for survey fieldwork, data collection and management, sample processing and storage, managed data sharing and consent for re-approaching participants, which can be utilised for further research studies. As such, the DDS represents a rich platform for investigating the distribution, interrelation and aetiology of chronic diseases and their risk factors, which is critical for developing health care policies for disease management and prevention. For data access enquiries please contact the African Partnership for Chronic Disease Research (APCDR) at data@apcdr.org or the corresponding author.
Enemy Jet History
Authors: Maguire D. R.
Published: February 2016

This paper gives details of the first flights of the German, Italian and Japanese jet-propelled aircraft and engines during the last war. Only gas turbine jet propulsion has been covered.
Analysis of anisotropic prismatic sectiosn
Authors: Hill G. F. J. , Weaver P. M.
Published: February 2016

The dynamic behaviour of rotor blades is often modelled using onedimensional beam analysis with equivalent mass and stiffness properties to those of the full blade. Calculation of accurate elastic stiffness terms for these arbitrarily shaped sections with differing material properties is vital to this process. A method which produces these properties using standard finite element analysis codes is presented. The method is then compared with theoretical results for a simple rectangular section beam and case studies are performed on a composite laminate and box-section.
Aerodynamic forces and moments on an ogive cylinder at incidence
Authors: Luo S.C. , Ng Y.T. , Lim T.T.
Published: February 2016

In flows over an ogive cylinder placed at incidence, it is well documented that a side force acts on the cylinder. However, little is known about the relation between the side force (CFy) and other force and moment components. In this note, the variations of three force and three moment components, acting on the ogive cylinder, with roll angle are measured simultaneously. The model was placed at four different angles-of-attack, namely α = 30°, 45°, 50° and 60° and the results show that in addition to CFy, the variation of CFz, CMx, and CMz with the roll angle also exhibit the square wave like behaviour at α = 45° and 50°, and with the same cross over φ positions, while CFx and CMy remain relatively constant irrespective of the roll angle. The magnitudes of CFx and CMy were found to increase with angle of attack and were thought to be due to the increase in normal frontal area.
Flow visualisation experiments for turbine film cooling
Authors: Coat C. A. , Lock G. D.
Published: February 2016

Flow visualisation experiments related to turbine film cooling have been conducted. These investigated the fluid mechanics of coolant ejection using a large-scale, flat-plate model at engine-representative Reynolds numbers in a low-speed tunnel with ambient-temperature mainstream flow. The coolant trajectories were captured using a fine nylon mesh covered with thermochromic liquid crystals, allowing measurement of gas temperature contours in planes perpendicular to the flow. Three injection geometries were assessed: cylindrical holes with stream-wise injection, cylindrical holes with cross-stream injection, and fan-shaped holes. The data demonstrated that the cylindrical holes produced discrete jets, which lifted off the surface at high coolant-to-mainstream momentum flux ratios; these jets were characterised by the kidney-shaped stream-tubes expected for injection into cross-flow. The jets injected with cross-stream momentum exhibited a more obvious kidney-shaped cross-section, which rotated with distance downstream of injection. The jets from the fan-shaped holes were attached to the surface even at high momentum flux ratios, were more diffuse, and exhibited two cores of high temperature. The trajectory visualisation data were used to interpret the adiabatic cooling effectiveness measured at the surface.
An investigation of the flight dynamic characteristics of gyroplanes by use of flight tests
Authors: Spathopoulos V. M.
Published: February 2016

An analysis is presented both of flight test and simulation data obtained from a gyroplane aircraft. This class of rotary-wing vehicle has found limited application in areas other than recreational flying, however the accident rate has been such that it has prompted the study of the configuration’s stability and control characteristics. It is concluded that the flight dynamic response of the gyroplane examined is dominated by a fast, non-stable mode, affecting all states and thus increasing pilot workload. Simulation results indicate that the position of the centre of gravity significantly influences the stability of this mode.
Enhancement of thrust reverser cascade performance using aerodynamic and structural integration
Authors: Butterfield J. , Yao H. , Price M. , Armstrong C. , Raghunathan S. , Benard E. , Cooper R. , Monaghan D.
Published: February 2016

This paper focuses on the design of a cascade within a cold stream thrust reverser during the early, conceptual stage of the product development process. A reliable procedure is developed for the exchange of geometric and load data between a two dimensional aerodynamic model and a three dimensional structural model. Aerodynamic and structural simulations are carried out using realistic operating conditions, for three different design configurations with a view to minimising weight for equivalent or improved aerodynamic and structural performance. For normal operational conditions the simulations show that total reverse thrust is unaffected when the performance of the deformed vanes is compared to the un-deformed case. This shows that for the conditions tested, the minimal deformation of the cascade vanes has no significant affect on aerodynamic efficiency and that there is scope for reducing the weight of the cascade. The pressure distribution through a two dimensional thrust reverser section is determined for two additional cascade vane configurations and it is shown that with a small decrease in total reverse thrust, it is possible to reduce weight and eliminate supersonic flow regimes through the nacelle section. By increasing vane sections in high pressure areas and decreasing sections in low pressure areas the structural performance of the cascade vanes in the weight reduced designs, is improved with significantly reduced levels of vane displacement and stress.
Achieving drag measurement accuracy from a high load capacity internal balance design
Authors: Porter R.
Published: February 2016

As one aspect of a balance research and development programme, engineers at the Aircraft Research Association (ARA) have addressed the unique problems associated with the design of an internal single piece balance suitable for small military type aircraft models that experience very high loads during a wind tunnel test. The paper details the nature of the problems and the stages undertaken in the design, manufacture and commissioning of an initial prototype balance followed by a re-designed version to meet the stringent requirements. Data from recent tests indicate the quality of the measurements and the suitability of the balance for the testing of fighter type aircraft.
Integrated design of flight simulator
motion cueing systems
Authors: Hosman R. , Advani S. , Haeck N.
Published: February 2016

An advanced design process applicable to the
specification of flight simulator cueing systems is
presented in this paper. This process is based on
the analysis of the pilot-vehicle control loop by
using a pilot model incorporating both visual and
vestibular feedback, and the aircraft dynamics.
After substituting the model for the simulated
aircraft, the analysis tools are used to adjust the
washout filter parameters with the goal of restoring
pilot control behaviour. This process allows the
specification of the motion cueing algorithm. Then,
based on flight files representative of the
operational flight envelope, the required motion
system space is determined. The motion-base geometry
is established based on practical limitations, as
well as criteria for the stability of the platform
with respect to singular conditions. With this
process the characteristics of the aircraft, the
tasks to be simulated, and the missions themselves
are taken into account in defining the simulator
motion cueing system.
Flight control system damage simulation
using freely flying models
Authors: Sadovnychiy S. , Ryzhenko A. , Betin A.
Published: February 2016

This article deals with a damage simulation of flight
control systems during a flight. As a subject of
flight tests the model of a classic aerodynamic
aircraft scheme is considered. This aircraft has
highly swept wings a moderate wing elongation and
all-moving horizontal tail surfaces. The diagrams of
flight parameters from flight tests of the freely
flying models with loss of a control surface in
flight are given. The investigation results for the
failures leading to a sharp drop in the stiffness of
the control units in the pitch channel are given.
The damage investigation in horizontal flight and in
complex manoeuvres is given.
Experiments on the hypersonic turbulent shock-wave/boundary-layer interaction and the effects of surface roughness
Authors: Prince S. A. , Vannahme M. , Stollery J. L.
Published: February 2016

An experimental investigation was performed to study the effects of surface roughness on the Mach 8·2 hypersonic turbulent shockwave–boundary-layer interaction characteristics of a deflected control flap configuration. In particular, the surface pressure and heat transfer distribution along a quasi-2D ramp compression corner model was measured for flap angles between 0° and 38°, along with a Schlieren flow visualisation study. It was found that surface roughness, of scale 10% of the hinge-line boundary layer thickness, significantly increased the extent of the interaction, while increasing the magnitude of the peak pressure and heat flux just aft of reattachment. The incipient separation angle for a fully turbulent, Mach 8·2 boundary layer with a hinge line Reynolds number of 1·44 × 106, was estimated at 28-29°, reducing to between 19-22° with the introduction of laminar sub-layer scale surface roughness.
Acoustic validation of a new code using particle wake aerodynamics and geometrically-exact beam structural dynamics
Authors: Nitzsche F. , Opoku D. G.
Published: February 2016

This paper describes the validation of a new code for prediction both aeroacoustic and aeroelastic behaviour of hingeless rotors. The structural component is based on a non-linear beam element model considering small strains and finite rotations, which uses a mixed variational intrinsic formulation. The aerodynamic component is built on a loworder panel method incorporating a vortex particle free-wake model. The aerodynamic and structural components are combined to form a closely coupled aeroelastic code that solves in the time-domain. The loading and thickness noise terms for the aeroacoustic calculations are calculated from the aerodynamic data using a formulation based on the Ffowcs Williams-Hawkings (FW-H) equation. The code is successfully validated for acoustic signature and BVI predictions using test cases from the HELINOISE program.
Flight handling qualities
Authors: Padfield G. D.
Published: February 2016

This paper describes the methodology and key results from the first three years of delivery of ‘Flight Handling Qualities’ (FHQ), a problem-based-learning core module for fourth year Master of Engineering (MEng) undergraduates in Aerospace Engineering and optional module for the Systems Engineering MSc Programme, at the University of Liverpool. The module aim is to equip students with the skills and knowledge required to tackle aircraft handling qualities (HQs) and related ‘whole aircraft’ problems. Students are presented with the theory of handling qualities engineering in a series of interactive lectures. The students work in teams of four or five and undertake a number of team-building exercises throughout the first semester. Teams are presented with the idea that the aircraft with its handling qualities is the focus for knowledge acquisition and skills development. Each team is given the task of assessing and quantifying the HQs of a particular aircraft in a particular role, and then developing fixes to any handling deficiencies they identify; the current aircraft include the Wright Flyer, Grob 115, Black Hawk, Bo-105 and XV-15. Teams write an interim report at the end of the first term and a final report at the end of the second term, showing how they have assessed the aircraft, developed solutions to the problems and made recommendations concerning the aircraft’s suitability in the defined role. The reports also address the technical feasibility and economic viability of the proposed upgrades. The teams present their work to mock ‘customers’ (group of staff, another student team, visiting Industrialists) with the objective of demonstrating that the aircraft is now fit for the role. Each individual student maintains a ‘personal learning journal’, in which they document the development of their understanding of handling qualities and, more general, transferable skills. The module is designed to enable students to engage in all elements of the conceive-design-implement-operate (CDIO) cycle.
Autonomy in unmanned air vehicles
Authors: Platts J. T.
Published: February 2016

The paper describes a key risk area threatening the widespread deployment of unmanned air vehicles (UAVs), that of attaining high levels of autonomy. Autonomy is loosely defined in the context of UAVs and the meaning of ‘level of autonomy’ discussed. The paper argues that the achievement of high levels of autonomy is not merely a function of increasing machine intelligence but also of maintaining the human operator’s engagement with the decision making process and retaining human authority. An assumption is that a human being in the loop will be a requirement for safety, flight clearance and legal reasons on early systems. Therefore, developers of highly autonomous systems are presented with a paradox. It will be argued that the human must be placed at the centre of the design process and consequently human factors, the human machine interface and the system architecture become critical to achieving high levels of autonomy. This quality impacts on the entire knowledge acquisition and design cycle and broadens what is meant by that term placing it as a discipline firmly in the systems design community. The paper concludes by outlining the key barriers to the successful development of highly autonomous UAVs.
On the vortex created by multiple blades joined at a hub
Authors: Spalart P. R.
Published: February 2016

Experimental studies often use several blades, joined on the centreline, to generate a vortex in a wind tunnel. The circulation profile of this vortex is non-trivial, and a rapid prediction method will facilitate the design of such devices. Prompted by an experiment of Beninati and Marshall, such a model was derived. It assumes a large number of narrow blades and small turning angles, and rests on a balance of angular momentum and on simple aerofoil function. It is claimed to be valid even close to the centreline, can be completed analytically, contains no adjustable constants, and agrees well with two experiments although the turning angle reached 16° and the devices only had two or four blades. With typical geometries, the interference between blades makes the circulation profile quite different from that behind an elliptically-loaded wing, prompting some doubt over the relevance of such a vortex to those trailing real wings.
A dynamic sampling scheme for GPS integrity assessment
Authors: Feng S. , Ochieng W. , Walsh D. , Ioannides R.
Published: February 2016

The Global Positioning System (GPS) is already being used for certain aviation applications and some safety critical air traffic services will be based on GPS. These air traffic services must achieve allowable levels of safety before they can be accepted. For this to occur, GPS based navigation systems must achieve a defined level of performance specified in terms of accuracy, integrity, continuity and availability. This must be determined by various analysis techniques including failure mode and effects analysis (FMEA) and integrity assessment. Because of the high percentile requirements placed on integrity (as the parameter most directly related safety), it is unfeasible to measure system performance by demonstration (field trial). Realistic simulation informed by some field experience is usually employed. However, the current simulation-based approaches for receiver autonomous integrity monitoring (RAIM) performance assessment have a number of weaknesses including the use of coarse (large) spatial and temporal sampling intervals, loose definitions of error and geometric correlations, a lack of sampling of all geometries and the inability to account for critical points due to uncorrelated factors.

This paper proposes a dynamic sampling method that takes account of these weaknesses, identifying dynamically only the required points for integrity performance assessment. Comprehensive simulations carried out to test the proposed approach for a single point, an area, and a non-precise approach (NPA) flight path to Gatwick airport in the United Kingdom show that the method can be effective in capturing all the points enabling a robust and reliable assessment of system integrity.
Corporate memory contribution to integrated design and analysis systems
Authors: Mendenhall M. R.
Published: February 2016

The recent decline in the USA aerospace industry has resulted in fewer programs, fewer engineers, and a potential loss of capability for future technology development. As engineers retire or leave the industry, their corporate memory or retained knowledge must be preserved for future use. A process to capture their expert knowledge is described, and a framework which provides a means to retrieve and use this valuable technical information is shown. Four examples of integrated design and analysis systems for four diverse technologies and applications are discussed.
Development of an aircraft systems dispatch reliability design methodology
Authors: Bineid M. , Fielding J. P.
Published: February 2016

This paper describes the development of a generic aircraft systems dispatch reliability design methodology (ASDRDM) that has been developed for use during early phases of the aircraft systems design process.

The methodology incorporates prediction of both reliability and maintainability through the aircraft design hierarchy, down to component level. It can be applied at the early design stage, but can also be used for advanced design phases and can use generic or actual failure rate and mean time to repair data. It allows designers to modify system architectures and component reliability and maintainability characteristics. The paper shows the validation that has been performed, and its use is demonstrated by a case-study.
Minimum forebody drag in hypersonic continuum and rarefied flows
Authors: Pike J.
Published: February 2016

Minimum drag shapes of given length and base area are investigated for hypersonic flow using both Newtonian impact theory and free molecular flow theory. The drag of Newton’s minimum drag body, which has previously been evaluated by numerical means, is derived as an analytic expression. The analytical results are applicable to a range of local pressure laws allowing minimum drag shapes obtained using impact theory to be directly compared with low density flow equivalents using free molecular flow. The low density shapes are found to have larger blunt regions at the nose and significantly larger drag coefficients. For free molecular flow the drag varies with the surface reflection characteristics. As the fraction of diffuse reflection at the surface increases, the drag increases and the sensitivity of the drag to changes in the minimum drag shape is reduced.
Cumulative global metamodels with uncertainty — a tool for aerospace integration
Authors: Reisenthel P. H. , Love J. F. , Lesieutre D. J. , Childs R. E.
Published: February 2016

The integration of multidisciplinary data is key to supporting decisions during the development of aerospace products. Multidimensional metamodels can be automatically constructed using limited experimental or numerical data, including data from heterogeneous sources. Recent progress in multidimensional response surface technology, for example, provides the ability to interpolate between sparse data points in a multidimensional parameter space. These analytical representations act as surrogates that are based on and complement higher fidelity models and/or experiments, and can include technical data from multiple fidelity levels and multiple disciplines. Most importantly, these representations can be constructed on-the-fly and are cumulatively enriched as more data become available. The purpose of the present paper is to highlight applications of these cumulative global metamodels (CGM), their ease of construction, and the role they can play in aerospace integration. A simple metamodel implementation based on a radial basis function network is presented. This model generalises multidimensional data while simultaneously furnishing an estimate of the uncertainty on the prediction. Four examples are discussed. The first two illustrate the efficiency of surrogate-based design/optimisation. The third applies CGM concepts to a data fusion application. The last example is used to visualise extrapolation uncertainty, based on computational fluid dynamics data.
Integrating CFD and piloted simulation to quantify ship-helicopter operating limits
Authors: Roper D. M. , Owen I. , Padfield G. D. , Hodge S. J.
Published: February 2016

This paper describes a study which has been concerned with numerical predictions of the airwakes resulting from two simplified ship geometries: the internationally agreed Simple Frigate Shape, SFS1, and its successor, SFS2. Extensive steady-state simulations have been carried out for a wide range of wind conditions using Fluent, a commercially available Computational Fluid Dynamics (CFD) code. The CFD predictions have been partially validated against wind tunnel data produced by the National Research Council of Canada (NRC) and have shown good agreement. The resulting airwake velocity components have been exported from Fluent, interpolated onto suitable grids and attached to the FLIGHTLAB flight-simulation environment as look-up tables; piloted flight trials were then carried out using the Liverpool full-motion simulator. The pilot workload and helicopter control margins resulting from a range of wind-over-deck conditions have been used to develop the Ship-Helicopter Operating Limits (SHOL) for a Lynx-like helicopter and the SFS2. The workload was compared to the pilot’s experiences on a similar aircraft and a Type 23 Frigate and the simulated SHOL compared with SHOLs derived from sea trials. The results are very encouraging and open up further the long awaited prospect of such simulations being used in the future to reduce at-sea trials, and to provide a safe environment for pilot training.
One CFD calculation to end point flight testing: (Has CFD finally replaced the wind tunnel?)
Authors: Cenko A.
Published: February 2016

Any time a new aircraft is introduced into service, or an old aircraft undergoes substantial modifications or needs to be certified to carry and employ new stores, the store separation engineer is faced with a decision about how much effort will be required to provide an airworthiness certification for the aircraft and stores. Generally, there are three approaches that have been used: wind-tunnel testing, computational fluid dynamics (CFD) analyses and flight testing. During the past twenty years there have been considerable advances in all three areas. In particular, there has been a considerable improvement in the speed and validity of CFD results for store separation. The Holy Grail of CFD has long been the reduction/replacement of wind-tunnel testing. This would mean in store separation the ability to go from a CFD calculation to flight testing at the end point. The paper will describe how this was achieved for the F/A-18C/Litening pod program.