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Polymyalgia rheumatica is an inflammatory rheumatic disease of the elderly characterised by pain and stiffness in the neck and pelvic girdle, and is the second most common inflammatory rheumatic condition in this age group, after rheumatoid arthritis. Polymyalgia rheumatica can occur independently or in association with giant cell arteritis, which is the most common form of primary vasculitis. The diagnosis of polymyalgia rheumatica is usually based on clinical presentation and increase of inflammatory markers. There are no pathognomonic findings that can confirm the diagnosis. However, different imaging techniques, especially ultrasonography, can assist in the identification of polymyalgia rheumatica. Glucocorticoids are the cornerstone of the treatment of polymyalgia rheumatica, but they might be associated with different adverse events. A subgroup of patients presents with a refractory disease course and, in these cases, adding methotrexate as a steroid-sparing agent could be useful. In this review, we summarise the latest findings regarding the pathogenesis, diagnosis and management of polymyalgia rheumatica and try to highlight the possible pitfalls, especially in elderly patients.

Der Trend zur kundenindividuellen Massenproduktion stellt klassische Produktionsmethoden kleinerer und mittlerer Unternehmen vor große Herausforderungen. Branchenübergreifend lässt sich feststellen, dass es für diese Unternehmen besonders schwierig ist mit klassischen Automationslösungen einen tragbaren Kompromiss für den Dreiklang aus hoher Flexibilität, hoher Produktionseffizienz und geringem Investitionsrisiko zu finden. Gleichzeitig stellt die Agilität zur Anpassung an variable Marktbedingungen eine typische Stärke kleiner und mittlerer Unternehmen dar.

Total rates of heat release, , and soot emission, , are studied in ethanol-N2/air and n-butanol-N2/air counterflow flames. A gas flame is first established as a base case and fractions of the gaseous fuel are then replaced by droplets and nitrogen, keeping the total fuel mass flux constant. Several values of the liquid to total fuel mass ratio, φl, are employed, covering the entire range from a gas flame to a spray flame (0 ≤ φl ≤ 1). Different initial droplet radii, R0, are considered, as well as both low and close to extinction strain rates. Results show qualitative similarities for both fuels, even though quantitative differences are observed. In general, ethanol flames release more heat and less soot than n-butanol flames. For low strain rates, φl = 1 leads to lower soot emissions than for the reference gas flame, independently of R0. Also, is higher for R0 = 25 and 40 μm. Close to extinction, increasing φl notoriously improved without considerably raising for R0 = 25 μm. Also, for R0 = 40 μm, there are some particular values of φl for which similar situations occur. These results show that the fuel injection phase plays an important role in optimizing combustion processes.

Funder: Engineering and Physical Sciences Research Council; doi: http://dx.doi.org/10.13039/501100000266, Funder: University of Cambridge, The modelling of scalar dissipation rate in conditional methods for large-eddy simulations is investigated based on a priori direct numerical simulation analysis using a dataset representing an igniting non-premixed planar jet flame. The main objective is to provide a comprehensive assessment of models typically used for large-eddy simulations of non-premixed turbulent flames with the Conditional Moment Closure combustion model. The linear relaxation model gives a good estimate of the Favre-filtered scalar dissipation rate throughout the ignition with a value of the related constant close to the one deduced from theoretical arguments. Such value of the constant is one order of magnitude higher than typical values used in Reynolds-averaged approaches. The amplitude mapping closure model provides a satisfactory estimate of the conditionally filtered scalar dissipation rate even in flows characterised by shear driven turbulence and strong density variation.

The lean blow-out performance of an engine and the ability to re-ignite the flame, especially at high-altitude conditions, are important aspects for the safe operability of airplanes. The operability margins of the engine could be extended if it was possible to predict the occurrence of flame blowout from in-flight measurements and take actions to dynamically control the flame behaviour before complete extinction. In this work, the use of Re-currence Quantification Analysis (RQA), an established tool for the analysis of non-linear dynamical systems, is explored to reconstruct and study the blow-off dynamics starting from pressure measurements taken from blow-off experiments of an engine rig. It is shown that the dynamics of the combustor exhibit chaotic characteristics far away from blow-off and that the dynamics become more coherent as the blow-off condition is approached. The degree of determinism and recurrence rate are studied during the entire combustor’s dynamics, from stable flame to flame extinction. It is shown that the flame extinction is anticipated by an increase of the degree of determinism and recurrence rate at all investigated conditions, which indicates intermittent behavior of the combustor before the blow-off condition is reached. Therefore, in the configuration investigated here, the determinism and the recurrence rate of the system could be good predictors of blow-off occurrence and could potentially enable control actions to avoid flame extinction. This study opens up new possibilities for engine control and operability. The development of real-time RQA should be addressed in future research.

A physics-based, low-order ignition model is used to assess the ignition performance of a kerosene-fueled gas-turbine combustor under high-altitude relight conditions. The ignition model used in this study is based on the motion of virtual flame particles and their extinction according to a Karlovitz number criterion, and a stochastic procedure is used to account for the effects of spray polydispersity on the flame’s extinction behavior. The effects of large droplets arising from poor fuel atomization at sub-idle conditions are then investigated in the context of the model parameters and the combustor’s ignition behavior. For that, a Reynolds-averaged Navier-Stokes simulation of the cold flow in the combustor was performed and used as an input for the ignition model. Ignition was possible with a Sauter mean diameter (SMD) of 50 μm, and was enhanced by increasing the spark volume. Although doubling the spark volume at larger SMDs (75 and 100 μm) resulted in the suppression of short-mode failure events, ignition was not achieved due to a reduction of the effective flammable volume in the combustor. Overall, a lower ignition probability is obtained when using the stochastic procedure for the spray, which is to be expected due to the additional detrimental effects associated with poor spray atomisation and high polydispersity.

Collaborative AI systems aim at working together with humans in a shared space to achieve a common goal. This setting imposes potentially hazardous circumstances due to contacts that could harm human beings. Thus, building such systems with strong assurances of compliance with requirements domain specific standards and regulations is of greatest importance. Challenges associated with the achievement of this goal become even more severe when such systems rely on machine learning components rather than such as top-down rule-based AI. In this paper, we introduce a risk modeling approach tailored to Collaborative AI systems. The risk model includes goals, risk events and domain specific indicators that potentially expose humans to hazards. The risk model is then leveraged to drive assurance methods that feed in turn the risk model through insights extracted from run-time evidence. Our envisioned approach is described by means of a running example in the domain of Industry 4.0, where a robotic arm endowed with a visual perception component, implemented with machine learning, collaborates with a human operator for a production-relevant task., 4 pages, 2 figures

We determine the complete space-time metric from the bootstrapped Newtonian potential generated by a static spherically symmetric source in the surrounding vacuum. This metric contains post-Newtonian parameters which can be further used to constrain the complete underlying dynamical theory. For values of the post-Newtonian parameters within experimental bounds, the reconstructed metric appears very close to the Schwarzschild solution of General Relativity in the whole region outside the event horizon. The latter is however larger in size for the same value of the mass compared to the Schwarzschild case., Comment: 27 pages, 3 figures, minor changes to match the accepted version in PRD

© 2017 The Combustion Institute In various applications with recirculation, liquid droplets can be immersed in gases that may have a wide range of possible compositions, from pure air to hot combustion products. In order to gain fundamental understanding of the behaviour of individual droplets in vitiated air, numerical simulations of kerosene single droplet evaporation, autoignition, and combustion in conditions relevant to gas turbines have been performed. The droplet autoignition behaviour has been analysed in both physical and mixture fraction space for a wide range of vitiated air compositions and initial droplet diameters. Results show that the autoignition time delay decreases with increasing level of dilution with hot combustion products and decreasing initial droplet diameter. Chemistry is confined up to a radius of almost 10 initial droplet diameters and the location of autoignition is influenced by both the initial droplet diameter and the level of dilution. The time evolution of species in the gaseous phase after autoignition shows similar trends for all the diameters and dilution levels investigated here with the peak of temperature and OH mass fraction moving towards the droplet surface as a consequence of the balance between fuel production and consumption. In mixture fraction space, the location of the peaks of temperature and OH mass fraction after autoignition do not change in time whereas other intermediate species such as CH 2 O and pyrolysis products still exhibit a quite variable behaviour. The long-time flame structure has been compared with gaseous laminar counterflow simulations and, although qualitatively similar, the flame structure in the two configurations has differences with implications for flamelet combustion models used in spray combustion. The droplet evaporation, autoignition, and combustion behaviour has been summarized through a regime diagram showing the evaporation and autoignition time delays as a function of both initial droplet diameter and vitiated air dilution. This allows the identification of different states in the droplet combustion scenario and the introduction of critical values of dilution and initial droplet diameter beyond which single droplet rather than cloud combustion can occur, which can be exploited in the design of lean burn gas turbine combustion systems. The approach presented here can be easily extended to other conditions and fuels allowing the generation of regime diagrams for various operating conditions.

We point out an association between anomalies in the Hawking quasilocal mass (or, in spherical symmetry, in its better known version, the Misner-Sharp-Hernandez mass) and unphysical properties of the spacetime geometry. While anomalous behaviors show up in certain quantum-corrected black holes, they are not unique to this context and signal serious physical pathologies of isolated gravitating systems in general., 8 pages, no figures

The present work studies the effect of entropy dispersion on the level of combustion noise at the turbine outlet of the Rolls-Royce ANTLE aero-engine. A new model for the decay of entropy waves, based on modeling dispersion effects, is developed and utilized in a low-order network model of the combustor (i.e., LOTAN code that solves the unsteady Euler equations). The proposed model for the dispersion of entropy waves only requires the mean velocity field as an input, obtained by Reynolds-averaged Navier–Stokes (RANS) computations of the demonstrator combustor. LOTAN is then coupled with a low-order model code (LINEARB) based on the semi-actuator disk model that studies propagation of combustion noise through turbine blades. Thus, by combining LOTAN and LINERAB, the combustion noise and its counterparts, direct and indirect noise, generated at the turbine exit are predicted. In comparison with experimental data, it is found that without the inclusion of entropy dispersion, the level of combustion noise at the turbine exit is overpredicted by almost 2 orders of magnitude. The introduction of entropy dispersion in LOTAN results in a much better agreement with the experimental data, highlighting the importance of entropy wave dispersion for the prediction of combustion noise in real engines. In more detail, the agreement with the experiment for high and low frequencies was very good. At intermediate frequencies, the experimental measurements are still overpredicted; however, the predicted noise is much smaller compared to the case without entropy dispersion. This discrepancy is attributed to (i) the role of turbulent mixing in the overall decay of the entropy fluctuations inside the combustor, not considered in the model developed for the decay of entropy waves, and (ii) the absence of a proper model in LINEARB for the decay of entropy waves as they pass through the turbine blade rows. These are areas that still need further development to improve the prediction of low-order network codes.

An ultralow emission combustor concept based on “flameless oxidation” is demonstrated in this paper for aviation kerosene. Measurements of gas emissions, as well as of the size and number of nanoparticles via scanning mobility particle sizing, are carried out at the combustor outlet, revealing simultaneously sootfree and single-digit NOx levels for operation at atmospheric conditions. Such performance, achieved with direct spray injection of the fuel without any external preheating or prevaporization, is attributed to the unique mixing configuration of the combustor. The combustor consists of azimuthally arranged fuel sprays at the upstream boundary and reverse-flow air jets injected from downstream. This creates locally sequential combustion, good mixing with hot products, and a strong whirling motion that increases residence time and homogenizes the mixture. Under ideal conditions, a clean, bright-blue kerosene flame is observed, free of soot luminescence. Although soot is intermittently formed during operation around optimal conditions, high-speed imaging of the soot luminescence shows that particles are subjected to long residence times at O2-rich conditions and high temperatures, which likely promotes their oxidation. As a result, only nanoparticles in the 2−10 nm range are measured at the outlet under all tested conditions. The NOx emissions and completeness of the combustion are strongly affected by the splitting of the air flow. Numerical simulations confirm the trend observed in the experiment and provide more insight into the mixing and air dilution.

Bootstrapped Newtonian gravity is a non-linear version of Newton's law which can be lifted to a fully geometric theory of gravity starting from a modified potential. Here, we study geodesics in the bootstrapped Newtonian effective metric in vacuum and obtain bounds on a free parameter from Solar System data and S-star orbits near our Galaxy centre. These bounds make vacuum bootstrapped Newtonian gravity experimentally indistinguishable from General Relativity., Comment: REVTeX 4, 11 pages, 5 figures, 5 tables. Version to appear in PRD

Collaborative robots (cobots) find increased use in industrial workspaces. The aspects of safety and ergonomics are important challenges when designing such workspaces. In this work Mixed Reality (MR) and Virtual Reality (VR) are used for the design of cobot workspaces in industrial environments. ROS (Robotic Operating System) together with Unity is used to simulate and visualize cobot applications. Simulated and real robotics are merged into one tool developed for Extended Reality (XR). To allow early planning in VR, existing industrial environments are reconstructed digitally using state-of-the-art 3-D laser scanners. VR and MR are then applied to test the developed scenarios in various environments, like variation of workspace or robot. In addition, an external tracking system allows us to monitor a human operator and to visualize ergonomics and to mitigate potential safety risks.

We consider the trajectory tracking optimization for an elastic joint robot with noisy joint-velocity readings and actuation torque limits. We propose an approach targeting the minimization of the trajectory tracking error, of the velocity noise amplification on the control commands, and of the trajectory execution time. We integrate the use of a feedforward/feedback trajectory tracking control scheme with efficient and accurate simulations of the controlled system dynamics. These are used within a genetic algorithm optimization scheme for optimizing the control gains and trajectory execution time. We verify the effectiveness of our proposed approach using simulations.

Context and motivation. Collaborative AI systems aim at working together with humans in a shared space. Building these systems, which comply with quality requirements, domain specific standards and regulations is a challenging research direction. This challenge is even more exacerbated for new generation of systems that leverage on machine learning components rather than deductive (top-down programmed) AI.

We review spherical and inhomogeneous analytic solutions of the field equations of Einstein and of scalar-tensor gravity, including Brans-Dicke theory, non-minimally (possibly conformally) coupled scalar fields, Horndeski, and beyond Horndeski/DHOST gravity. The zoo includes both static and dynamic solutions, asymptotically flat, and asymptotically Friedmann-Lema\^itre-Robertson-Walker ones. We minimize overlap with existing books and reviews and we place emphasis on scalar field spacetimes and on geometries that are "general" within certain classes. Relations between various solutions, which have largely emerged during the last decade, are pointed out., Comment: 140 pages, one figure. Explanation text and bibliography expanded, typographical errors corrected. Matches version to appear in Physics Reports

We study the location of marginally trapped surfaces in space-times resulting from an axial deformation of static isotropic systems, and show that the Misner-Sharp mass evaluated on the corresponding undeformed spherically symmetric space provides the correct gravitational radius to locate the spheroidal horizon., 16 pages in REVTeX format, 1 figure, with streamlined calculation of expansion scalars. Title changed. arXiv admin note: text overlap with arXiv:1801.05621

A reactive Molecular Dynamics (MD) study of toluene oxidation at high temperatures under externally applied electrostatic fields has been performed. The impact of the modeling of local charge distribution has been investigated by comparing the widely used Charge Equilibration (QEq) method with the Charge Transfer with Polarization Current Equalization (QTPIE) method, which shields charge transfers up to atomic orbitals and introduces molecular polarization. Using the latter method, it is possible to improve the computation of the atomic charges, which are a critical aspect for the numerical study of electric fields, and to capture important effects of the electric field on rotational and vibrational energies of the toluene molecule. Results show that a more comprehensive treatment of inter- and intramolecular charge distribution achieved through the QTPIE method leads to substantially different applied forces and oxidation rates of toluene compared to the QEq method. Using the QTPIE method, no significant effects of the electrostatic field on the toluene oxidation rate were observed for the range of temperatures and pressures studied here, which is in disagreement with the results obtained with the QEq method where a clear impact of the electrostatic field on the average oxidation rate was found. Therefore, when studying electric field effects with MD simulations, the choice of the method used for the charge equilibration is a key modeling assumption whose impact should be carefully evaluated.

We report a new one-parameter family of spherically symmetric, inhomogeneous, and time-dependent solutions of the vacuum Brans-Dicke field equations which are conformal to the Roberts scalar field geometries of Einstein gravity. The new solution is spherical and time-dependent and contains a naked central singularity. We use it as a seed to generate another two-parameter family of solutions using a known symmetry of vacuum Brans-Dicke gravity., 6 pages, no figures. Title changed. Updated to match the published version

The development of better laser-based experimental methods and the fast rise in computer power has created an unprecedented shift in turbulent combustion research. The range of species and quantities measured and the advent of kHz-level planar diagnostics are now providing great insights in important phenomena and applications such as local and global extinction, pollutants, and spray combustion that were hitherto unavailable. In simulations, the shift to LES allows better representation of the turbulent flow in complex geometries, but despite the fact that the grid size is smaller than in RANS, the push towards realistic conditions and the need to include more detailed chemistry that includes very fast species and thin reaction zones emphasize the necessity of a sub-grid turbulent combustion model. The paper discusses examples from current research with experiments and modelling that focus on flame transients (self-excited oscillations, local extinction), sprays, soot emissions, and on practical applications. These demonstrate how current models are being validated by experimental data and the concerted efforts the community is taking to promote the modelling tools to industry. In addition, the various coordinated International Workshops on non-premixed, premixed, and spray flames, and on soot are discussed and some of their target flames are explored. These comprise flames that are relatively simple to describe from a fluid mechanics perspective but contain difficult-to-model combustion problems such as extinction, pollutants and multi-mode reaction zones. Recently, swirl spray flames, which are more representative of industrial devices, have been added to the target flames. Typically, good agreement is found with LES and some combustion models such as the progress variable - mixture fraction flamelet model, the Conditional Moment Closure, and the Transported PDF method, but predicting soot emissions and the condition of complete extinction in complex geometries is still elusive.

A novel effervescent buffered solution of 70 mg alendronate (ALN-EX) was developed to improve upper gastrointestinal (GI) tolerability over alendronate tablets (ALN-T). Whether a better GI tolerability can improve persistence remains to be determined. This study evaluated persistence and reasons for discontinuation in patients treated with ALN-EX compared to a historical cohort on ALN-T. Post-menopausal women (PMW) from a standardized clinical database with BMD T-score

Fractional Newtonian gravity, based on the fractional generalization of Poisson's equation for Newtonian gravity, is a novel approach to Galactic dynamics aimed at providing an alternative to the dark matter paradigm through a non-local modification of Newton's theory. We provide an in-depth discussion of the gravitational potential for the Kuzmin disk within this new approach. Specifically, we derive an integral and a series representation for the potential, we verify its asymptotic behavior at large scales, and we provide illuminating plots of the resulting equipotential surfaces., 13 pages, 8 figures, published in EPJ Plus

Following an existing procedure in general relativity, the turnaround radius of a spherical structure is studied in scalar-tensor gravity using a new prescription for the analog of the Hawking-Hayward quasilocal mass in this class of theories., 10 pages, no figures, to appear in Phys.Rev.D

A low calcium intake is associated with an increased fracture risk. We assessed the dietary calcium intake in a cohort of Italian individuals evaluated for low bone mineral density (BMD). A 7-day food-frequency questionnaire was administered to 1793 individuals consecutively referred at a Centre of the Italian Society for Osteoporosis, Mineral Metabolism and Skeletal Diseases for low BMD. In 30.3% (544/1793) and 20.9% (374/1793) of subjects the calcium intake was inadequate ( 1200 mg/day), respectively. Patients with calcium intake 700 mg/day (5.3%, 3.0%, 4.1%, respectively, p

Sickle-cell disease (SCD) is a worldwide distributed hemoglobinopathy, characterized by hemolytic anemia associated with vaso-occlusive events. These result in acute and chronic multiorgan damage. Bone is early involved, leading to long-term disability, chronic pain and fractures. Here, we carried out a retrospective study to evaluate sickle bone disease (SBD) in a cohort of adults with SCD. We assessed bone density, metabolism and turnover. We also evaluated the presence of fractures and the correlation between SCD severity and skeletal manifestations. A total of 71 patients with SCD were analyzed. The mean age of population was 39 &plusmn, 10 years, 56% of which were females. We found osteoporosis in a range between 7% and 18% with a high incidence of vertebral fractures. LDH and AST were predictive for the severity of vertebral fractures, while bone density was not. Noteworthy, we identified -1.4 Standard Deviations T-score as the cutoff for detecting the presence of fractures in patients with SCD. Collectively our data allowed us to develop an algorithm for the management of SBD, which may be useful in daily clinical practice to early intersect and treat SBD.

Within the framework of the project “Strengthening Disaster Management Capacity of Women in Guyana and Dominica”, the National Flood Early Warning System (NFEWS) for Guyana is currently under development. The technical component of the system aims at implementing an operational flood forecasting modelling chain linking meteorological, hydrological and inundation models to provide timely early warnings and predicted flood scenarios, allowing the decision maker to take prevention actions and reduce the impacts of the forecasted event.The objective is to implement, together with the Hydromet Service of Guyana, a technical tool able to provide daily forecasts of extreme flood events 1 to seven 7 days in advance, up to the local scale of inundation maps for selected locations.The forecasting chain implemented is composed of five (5) main components: i) the weather forecasts, using the limited area WRF model executed twice a day at Hydromet; ii) observational inputs preparation, in particular rain maps through conditional merging between local ground stations and satellite information; iii) rainfall downscaling in several equiprobable scenarios using RAINFARM stochastic model; iv) the distributed hydrological model CONTINUUM, able to estimate river discharge and soil moisture conditions from the meteorological inputs (observation and forecasts), and v)the hydraulic model HYDRA-2D, that using a simplification of the shallow water equations allows fast and reliable inundation mapping.At four (4) selected locations, corresponding to relevant flood-prone communities in Guyana, an innovative coupling between the hydrological and the inundation models allows to trigger an operational execution of several hydraulic simulations, resulting in real-time probabilistic forecast of inundation maps. The outflow volumes, derived from CONTINUUM hydrological routing, for different rainfall scenarios are used as inflow inputs for HYDRA-2D. Scalability between hydrological (1.5km) and hydraulic (12m) scales has been achieved through detailed field data collection, that was also used, together with local knowledge, to calibrate the inundation model.Through the complete flood forecasting chain set up for Guyana, probability of exceeding significant water depths can be provided in advance to involved stakeholders, triggering early actions and thus enhancing flood resilience at the local scale.The hydrological component of the forecasting chain has been implemented at the national level for the whole country, at a feasible spatial and temporal resolution based on a balance between input data availability and expected response time for civil defense activities.Being developed using an open source model, as for all the other elements of the forecasting system, the hydraulic modelling component can be, in future, extended and replicated in other areas of interests.

Logistics in construction sites represents one of the main causes of musculoskeletal disorders for workers in the long run. For this reason, logistics represents a task that is highly suitable for automation. However, the application of robotics in construction is hindered by the on-site environment, which is often unstructured and subject to frequent change. To tackle this problem, the system proposed in this paper is a collaborative robotic platform aimed at human-centered applications on-site. The platform follows an operator while it carries heavy loads, such as materials and equipment, and it stops when it is near to the assisted worker. The system does not only avoid obstacles that are detected by its sensors, but it also navigates thanks to its knowledge of geometric and semantic information of the building project. This is achieved through a bridge between the Robot Operating System and the project data contained in the Building Information Model. The proposed system was developed and tested in laboratory, where it followed an operator while avoiding dynamic obstacles and areas marked in the building project file. This system represents a step forward towards the application of on-site collaborative construction robots.

The Mittag-Leffler function is universally acclaimed as the Queen function of fractional calculus. The aim of this work is to survey the key results and applications emerging from the three-parameter generalization of this function, known as the Prabhakar function. Specifically, after reviewing key historical events that led to the discovery and modern development of this peculiar function, we discuss how the latter allows one to introduce an enhanced scheme for fractional calculus. Then, we summarize the progress in the application of this new general framework to physics and renewal processes. We also provide a collection of results on the numerical evaluation of the Prabhakar function., 35 pages, 1 figure, Matches the version accepted in FCAA

Soot particle size distribution (PSD) evolution in an ethylene lab-scale swirl Rich-Quench-Lean (RQL) combustor is investigated using a detailed physicochemical sectional soot model coupled with the Conditional Moment Closure turbulent combustion model and Large Eddy Simulation. The aim is to develop predictive capability for the local soot PSD and to explore di erences in soot PSDs with di erent conditions of a burner con guration widely used in practice for emissions control. Two such conditions are studied by varying the air ow provided in the burner primary and dilution regions, which has a drastic e ect on soot emission as shown by previous experiments. The results show a reasonably good agreement with experiments for the mean reaction zone and soot locations and their variations with dilution. The predicted PSDs at the burner exit are fairly well captured for the high-dilution condition but show too few and too small particles for the dilution-free condition, which may be due to an overprediction of the oxidation rates or the unity Lewis number assumption used here that enhances penetration of soot towards the oxidiser stream. The results are analysed to reveal the hierarchy of reaction pathways during soot evolution and indicate how dilution air modi es the soot PSD within the primary zone. In particular, the presence of dilution leads to a broadly sustained uni-modal soot PSD shape and a decrease in particle size. The results demonstrate a framework for capturing soot PSD in realistic combustion devices, which may help meet future regulations based on particle number and size distribution., EPSRC Doctoral Training Award

A recent generalization of the Hawking-Hayward quasilocal energy to scalar-tensor gravity is adapted to general spherically symmetric geometries. It is then applied to several black hole and other spherical solutions of scalar-tensor and $f({\cal R}) $ gravity. The relations of this quasilocal energy with the Abreu-Nielsen-Visser gauge and the Kodama vector are discussed., Comment: 11 pages, no figures, to appear in Class.Quant.Grav

I provide a derivation of some characteristic effects of Milgrom's modified Newtonian dynamics (MOND) from a fractional version of Newton's theory based on the fractional Poisson equation. I employ the properties of the fractional Laplacian to investigate the features of the fundamental solution of the proposed model. The key difference between MOND and the fractional theory introduced here is that the latter is an inherently linear theory, featuring a characteristic length scale $\ell$, whilst the former is ultimately nonlinear in nature and it is characterized by an acceleration scale $a_0$. Taking advantage of the Tully-Fisher relation, as the fractional order $s$ approaches $3/2$, I then connect the length scale $\ell$, emerging from this modification of Newton's gravity, with the critical acceleration $a_0$ of MOND. Finally, implications for galaxy rotation curves of a variable-order version of the model are discussed., Comment: 7 pages, 2 figures. Title changed. Updated to match the published version

In a recent paper, Zhou et al. [Mech Time-Depend Mater (2017) 21: 151] studied the time-dependent properties of Glass Fiber Reinforced Polymers composites by employing a new rheological model with a time-dependent viscosity coefficient. This rheological model is essentially based on a generalized Scott-Blair body with a time-dependent viscosity coefficient. Motivated by this study, in this note we suggest a different generalization of the Scott-Blair model based on the application of Caputo-type fractional derivatives of a function with respect to another function. This new mathematical approach can be useful in viscoelasticity and diffusion processes in order to model systems with time-dependent features. In this paper we also provide the general solution of the creep experiment for our improved Scott-Blair model together with some explicit examples and illuminating plots., 7 pages, 3 figures, matches the published version

This work investigates the effects of premixed combustion kinematics in pre-chamber volumes on the development of emitted hot jets from the igniter. The effects of fuel type, orifice diameter, and ignition location are evaluated experimentally, with high-speed OH∗ and CH∗ chemiluminescence imaging, and computationally with Large-Eddy Simulations (LES). The imaging experiments allowed for simultaneous viewing of combustion processes within a quartz chamber and of the developing jet flow. Results from these experiments provided insight on the temporal evolution of the jet relative to the growth of an ignited kernel within the chamber, as well as information on the emission or lack of emission of radical species from the chamber. Computational results provided data on the temporal behavior of the pressure within the chamber and profiles of the high velocity flow through the orifice. These results, combined, have shown that dependent on the strain rate and effective orifice size, local quenching of radical species at the orifice occurs which fundamentally change whether hot products, reactive layers, or both are present in the turbulent jet emission. The dynamic structure and composition of the turbulent jet controls its relevance as an effective ignition source.

A high proportion of patients with fragility fracture, mainly hip fracture, have a variable degree of comorbidity and show some degree of dependence in basic or more complex activities of daily living. Evaluating these patents following the geriatric concept of frailty, about one third of hip fracture patients may be categorised as frail with high risk of poor outcomes and prolonged length of stay, one third as not frail, and about one third with an intermediate condition. Due to the high vulnerability, combined with the hip fracture event and surgical repair procedures, a multidisciplinary approach that includes geriatric competencies becomes essential to improve short and long-term outcomes after hip fracture. A key element of an effective process of care is a true co-managed approach that applies quality standards and provides a fast-track pathway of care, minimises the time the patient spends in bed, and reduces postoperative complications by means of standardised procedures. The occurrence of a fragility fracture is the strongest risk factor for a subsequent fracture. Moreover, frail subjects have a further risk of fracture due to high risk of falls - related to loss of muscle mass, multiple illnesses, impaired balance and weakness. Thus, effective secondary prevention strategies are essential to reduce morbidity and mortality after hip fracture, and they are currently a standard task of orthogeriatric care. Fracture liaison services (FLS) are probably the most efficient way of addressing secondary prevention including the assessment of both bone health and falls risk. Therefore, the optimal management of frail patients with fragility fracture includes both orthogeriatric care and FLS, which are complementary to each other. Orthogeriatric collaboration is also powerful in influencing healthcare policy. British experience as well as that in Ireland, Australia and New Zealand, have shown that when two widely disparate specialisms say the same thing, they may achieve a fundamental shift in attitudes and behaviour of both managers and clinicians. Furthermore, a continuous real-time audit, at national level, is a powerful driver for change and better standards of care.

We consider the problem of automatically designing model-based controllers of modular robot manipulators in a systematic way. Modular robots are especially useful in flexible manufacturing, where one wishes to quickly assemble robots from a set of modules for temporary tasks. The evaluation of all possible dynamical models is typically impractical, undermining the implementation of model-based control laws. Contrary to most other work that approached this challenge by designing decentralized controllers, we generate on-the-fly model-based centralized controllers after a new robot has been assembled. In this brief, we extend the applicability of our previous work on this subject by considering both link and joint modules, assembly dependent friction effects, and we finally present experiments that validate the overall approach.

To investigate the relationship between onset of delirium and time to surgery in hip fracture (HF) patients with a different degree of cognitive impairment. Retrospective analysis of a prospective database of 939 older adults, aged ≥ 75 years admitted with a fragility HF. Subjects underwent a Comprehensive Geriatric Assessment on admission, evaluating health status, prefracture functional status in basic and instrumental activities of daily living, and walking ability. According to the Short Portable Mental Status Questionnaire score, patients were stratified into three categories: cognitively healthy (0–2 errors), mildly to moderately impaired (3–7 errors) and severely impaired (8–10 errors). Time to surgery (from admission) was expressed as days. The occurrence of delirium was ascertained daily by Confusion Assessment Method. Two hundred ninety-two (31.1%) patients experienced delirium during in-hospital stay. They were older, with a higher degree of comorbidity and functional impairment compared to patients without delirium. In multivariate analysis, surgical delay resulted a significant independent risk factor for delirium (HR 1.11, 95% CI 1.01–1.24), along with age, prefracture functional disability and cognitive impairment. When the analysis was performed accounting for the cognitive categories, surgical delay demonstrated to increase the risk of delirium only in the subcategory of mildly to moderately impaired patients, while no significant effect was demonstrated in patients cognitively healthy or severely impaired. The study supports the concept that older adults with HF should undergo surgery quickly. Patients with mild-to-moderate cognitive impairment should be primarily considered as the best target for interventions aiming to reduce time to surgery.

How do I automate this task? This is a crucial question for production engineers. In classical industrial automation (think of a car factory) robots perform a small set of tasks for long periods of time. They were selected because their kinematic structure and strength suited the task requirements, and their motions were pre-programmed by a skilled programmer. In flexible manufacturing environments, tasks may change daily or hourly. The classical approach to automation is less suitable here: buying a dedicated robot for each set of tasks is uneconomical and coding each task is too time consuming. Further, qualified programmers with the requisite knowledge might not be available. To solve these problems, we propose a framework for modular robots that determines their structure and program based on human demonstrations.

This paper presents a set of numerical analyses carried out on a model combustor equipped with a prefilming airblast injection system using a multi-coupled approach that includes the solution of th...

© 2018, © 2018 A.M. Kypraiou, P.M. Allison, A. Giusti, and E. Mastorakos. The response of three flames with different degrees of premixedness (fully premixed, non-premixed with radial, and non-premixed with axial fuel injection) to acoustic oscillations is studied experimentally. The flames were imaged using OH* chemiluminescence and OH planar laser-induced fluorescence at 5 kHz. In addition to a flame kinematics analysis, the amplitude dependence of the transfer function was calculated. The dominant spatial structures of the heat release and their periodicity were examined using the proper orthogonal decomposition (POD) method. The Non-Premixed system with Radial fuel injection (NPR) showed the highest response to acoustic forcing, followed by the fully premixed and the Non-Premixed system with Axial fuel injection (NPA). In addition, the response of the non-premixed system with radial fuel injection was greater than that of the fully premixed system for various bulk velocities U, global equivalence ratios φ, forcing amplitudes A, and forcing frequencies f. In the fully premixed system, the heat release modulation was mainly through flame surface area modulation, while in the NPR system, both the flame area and the equivalence ratio modulations were found to be important mechanisms of the heat release oscillations. About 70% of the energy of the total fluctuations in the NPR case was contained in the first four POD modes, a percentage that decreased with overall equivalence ratio, but only this dropped to about 40% for the NPA flame. The frequency spectra of the coefficients of the POD modes exhibited peaks at the forcing frequency, with increasing broadband contributions in higher modes and for the NPA flame.

In this paper, after a brief review of the general theory concerning regularized derivatives and integrals of a function with respect to another function, we provide a peculiar fractional generalization of the $(1+1)$-dimensional Dodson's diffusion equation. For the latter we then compute the fundamental solution, which turns out to be expressed in terms of an M-Wright function of two variables. Then, we conclude the paper providing a few interesting results for some nonlinear fractional Dodson-like equations., 10 pages, 3 figures

In recent years, the price pressure and demand for personalised products in manufacturing increased continuously. As a reaction, technologies from the Information and Communication Technology (ICT) sector are applied by the industry, this trend is also known as digitalisation or Industry 4.0. Digitalisation might be effectively supported by simulation of production lines and will become crucial for manufacturing companies who want to benefit from the advances in ICT technologies, thus improving efficiency and competitiveness. Many agent-based simulators exist, nevertheless, most of them were developed for biological and social sciences whose use and specifications differ significantly from industrial applications. The commercial ones are expensive in terms of licensing, support and require specific training. We propose a communication concept for the simulator that we are developing called DeConSim, which aims at decentralized systems and is composed of several modules (representing resources, each with its own task and intelligence) and a core. DeConSim is capable of operating in two different modes: simulation mode and realtime mode. The former is used to achieve pure simulation results as fast as possible. The latter operates in real-time enabling DeConSim, in contrast to other existing simulators, to become the operational core of the control communication infrastructure of a real production line.

The introduction of Industry 4.0 leads to new decision-making scenarios in the construction industry. The construction sector still hesitates to adopt emerging technologies and many construction companies require support in the field of digitalisation and automation of processes. One way to support this sector is the use of decision support systems that perform a careful assessment of the feasibility for replacing traditional systems with automated ones. However, the design and the development of decision support systems is a complex and time-consuming task. In this work we apply Axiomatic Design to define design guidelines for the development of decision support systems in construction equipment selection. The needs of the construction industry for decision support in these scenarios are derived from existing literature in the field of construction and the key characteristic of decision-theoretic expert systems. These needs are analysed and translated into functional requirements. Then, through a mapping and decomposition process, the design solutions for the development of a decision support system are deduced. Functional requirements and design solutions are transformed into design guidelines that support the systematic development and implementation of decision support systems for the construction phase of a building.