bluuebunny/crossref_metadata_2025 huggingface dataset:
Droplet dynamics on slippery surfaces: small droplet, big impact
Authors: Liu Yahua , Yan Xiantong , Wang Zuankai
Published: May 2019

The dynamic interaction of droplets with slippery surfaces is essential to various industrial applications, such as anti‐icing, water‐repellency or water‐harvesting, anti‐bacterial, and phase change heat transfer. With recent progress in materials, manufacturing as well as learning from nature, the physics of droplet dynamics has been greatly enriched owing to the emergence of peculiar wetting states manifested on bio‐inspired textured surfaces. This review is devoted to the discussion of the recent progress made in the authors’ understanding of the dynamic interaction of small droplets with bio‐inspired surfaces. Particular attention is given to droplet impact on slippery surfaces, such as superhydrophobic surfaces characterised with air–solid–liquid triple‐phase interface and slippery lubricant infused porous surfaces characterised with the liquid/liquid two‐phase interface. Droplet spreading, retraction, contact time, elastodynamics as well as oblique impact are systematically reviewed. Finally, the authors offer their perspectives on this important and highly multidisciplinary research area.
Low‐loss and broadband coaxial line to air‐filled substrate integrated waveguide transition
Authors: Moznebi A.‐R. , Arsanjani A. , Afrooz K. , Mousavi P.
Published: May 2019

This Letter introduces a low‐loss and broadband coaxial line to air‐filled substrate integrated waveguide (AFSIW) transition for the first time. The fabrication of this transition involves three substrate layers. The inner conductor of the coaxial line is connected to the metal layer of the lower substrate and its outer conductor is connected to the metal layer of the upper substrate. This transition uses a taper‐shaped configuration at the end of the line to achieve the better impedance matching and wider matching bandwidth. In the previously reported AFSIW components, several transitions are used to transform the transverse electromagnetic mode of the coaxial line to the TE mode of the AFSIW structure. By using the proposed transition, these extra transitions are eliminated, which leads to the size and loss reduction of the structure. For validation purposes, a prototype of the back‐to‐back coaxial line to AFSIW transition is fabricated and measured for the entire C‐band. The simulated and measured results are in good agreement. The proposed transition achieves the measured insertion loss of 0.55 0.5 dB (0.28 0.25 dB for the transition) and return loss of better than from 4 to 8 GHz.
Effect of long‐term fluorination on surface electrical performance of ethylene propylene rubber
Authors: Men Rujia , Lei Zhipeng , Han Tao , Fabiani Davide , Li Chuanyang , Vincenzo Suraci Simone , Wang Jian
Published: May 2019

To investigate the effect of fluorination on surface electrical performance of ethylene propylene rubber (EPR), four pieces of EPR specimens are prepared and fluorinated for different duration ranging from 120 min to 480 min. The surface morphology and element compositions of experimental specimens are tested. The surface potential decay and complex permittivity are measured. The tracking discharge property and the erosion properties after tracking test are investigated. The surface charge transport and electrical property tailoring mechanism are discussed. The results show that when the fluorination duration is from 120 min to 360 min, the surface morphology gradually becomes flat and compact with time, and the surface resistance to electrical tracking is improved. While an excessive fluorination with the duration of 480 min leads to a significant increase in surface conductivity and a weakening in the resistance to electrical tracking, which is mainly due to a change in surface morphology. The recommended fluorination duration for an optimised surface property is between 240 and 360 min for EPR specimen.
Health monitoring and prognosis of electric vehicle motor using intelligent‐digital twin
Authors: Venkatesan Suchitra , Manickavasagam Krishnan , Tengenkai Nikita , Vijayalakshmi Nagendran
Published: May 2019

Electric mobility has become an essential part of the future of transportation. Detection, diagnosis and prognosis of fault in electric drives are improving the reliability, of electric vehicles (EV). Permanent magnet synchronous motor (PMSM) drives are used in a large variety of applications due to their dynamic performances, higher power density and higher efficiency. In this study, health monitoring and prognosis of PMSM is developed by creating intelligent digital twin (i‐DT) in MATLAB/Simulink. An artificial neural network (ANN) and fuzzy logic are used for mapping inputs distance, time of travel of EV and outputs casing temperature, winding temperature, time to refill the bearing lubricant, percentage deterioration of magnetic flux to compute remaining useful life (RUL) of permanent magnet (PM). Health monitoring and prognosis of EV motor using i‐DT is developed with two approaches. Firstly, in‐house health monitoring and prognosis is developed to monitor the performance of the motor in‐house. Secondly, Remote Health Monitoring and Prognosis Centre (RHMPC) is developed to monitor the performance of the motor remotely using cloud communication by the service provider of the EV. The simulation results prove that the RUL of PM and time to refill the bearing lubricant obtained by i‐DT twins theoretical results.
Edge detection of retinal OCT image based on complex shearlet transform
Authors: Xiaoming Liu , Ke Xu , Peng Zhou , Jiannan Chi
Published: May 2019

Aiming at the problem that optical coherence tomography (OCT) images with low contrast and layer structure blur are difficult to be automatically layered, a new OCT detection method based on complex shearlet transform is proposed. The method utilises nearly optimal sparse approximation singular curves of multi‐scale shearlet transform, and the contrast invariance of the phase congruence method. Compared with the Canny edge detector and wavelet methods, the complex shearlet‐based method achieved the highest Pratt figure of merit (PFOM) value. The PFOM value of a step type edge is 0.92, and that of a pulse type edge is 0.98. Three types of OCT images were tested, including normal retinal macula area, dry age‐related macular degeneration, and Stargardt disease. The experimental results show that the complex shearlet‐based method can detect more layered structures of OCT images, especially the boundary between the ganglion cell layer and the inner plexiform layer that is difficult to detect, and it can detect various types of OCT images. The complex shearlet‐based transform method provides an effective and general way to measure retinal OCT images.
Multimode resonator‐assisted dual band notch UWB antenna with additional bluetooth resonance characteristics
Authors: Gorai Abhik , Ghatak Rowdra
Published: May 2019

A compact planar integrated ultra‐wideband (UWB) and Bluetooth antenna are presented in this study. The basic radiator is circular in shape with a wide slit in it to accommodate a space optimised T‐shaped stub for Bluetooth frequency band. The proposed antenna is CPW‐fed with bevelled ground planes for the purpose of improvement in input impedance matching. A novel multimode resonator at the back of the substrate is responsible for the creation of two‐notched band at 5.5 and 8.1 GHz. The antenna exhibits an operational bandwidth of 3.–12 GHz for UWB application. The proposed antenna also has Bluetooth resonance characteristics at 2.4 GHz. The overall size of the antenna is 14 × 32 × 1.59 mm3. The antenna has a peak realised gain of 4 dBi and a constant group delay. The radiation pattern is also stable throughout the operational bandwidth. A fabricated prototype is developed and tested. Results obtained from electromagnetic simulation, equivalent circuit model, and measurement are in good agreement.
Bracketed stub loaded single layer rectangular microstrip antenna: A novel approach for modulation of magnetic field locus to achieve improved matching, and low cross polarisation
Authors: Pawar Umesh Ankush , Ghosh Abhijyoti , Chakraborty Subhradeep , Lolit Kumar Singh L. , Chattopadhyay Sudipta , Sim Chow‐Yen‐Desmond
Published: May 2019

In this work, the modulation of the magnetic field locus beneath a microstrip antenna due to placement of feeding probe has been exploited to evolve a simplified single element single layer structure for improved impedance matching and radiation performance. Unlike the earlier investigations, the present study tackles the issue of cross‐polar radiation of microstrip antenna due to its own dominant TM10 mode by achieving the uniformity of field distribution between lower‐ and upper‐half‐sections of a patch to suppress the effective orthogonal radiations (cross‐polar radiations) from the patch corners, without bothering the orthogonal and higher order resonances. Unlike the earlier approaches available in the literature, no slot or short has been made on the patch surface and in the ground plane to suppress cross‐polar radiation, which makes the present structure extremely simple. The proposed bracketed stub‐loaded single layer rectangular microstrip antenna structure exhibits high gain of 8 dBi with 27 dB of co‐cross polar isolation in H plane. The two‐element array constituted with same structure has also been examined and 10 dBi gain with >27 dB of co‐cross polar isolation is obtained. The obtained results are theoretically justified with simulation and measurement.
Probabilistic direct load flow algorithm for unbalanced distribution networks considering uncertainties of PV and load
Authors: Fu Yang , Liu Huanhuan , Su Xiangjing , Mi Yang , Tian Shuxin
Published: May 2019

The increasing penetration of distributed generations such as rooftop photovoltaics (PVs) brings about great challenges to distribution network planning and operation, due to the great uncertainty and intermittence. Although many probabilistic load flow (PLF) approaches have been proposed to handle uncertainties in power systems, PLFs for unbalanced distribution networks with superior computational performance are still under demand. Therefore, this study presents a novel PLF algorithm for unbalanced distribution networks considering the uncertainties introduced by PVs and loads. Taking PVs and loads as the random inputs while three‐phase voltages and network loss as the random outputs, the proposed PLF integrates the cumulant method and the Gram–Charlier expansion with the advanced direct load flow (DLF) approach to effectively address the unbalanced distribution PLF problems. Finally, the effectiveness and superior performance in terms of efficiency, accuracy, and robustness of the proposed PLF algorithm are verified by detailed simulations and compared with the Monte–Carlo Simulation method on a real Australian unbalanced distribution network.
Conductivity‐based model for the simulation of homocharges and heterocharges in XLPE high‐voltage direct current cable insulation
Authors: Jörgens Christoph , Clemens Markus
Published: May 2019

The dynamic space charge distribution within cross‐linked polyethylene (XLPE) cable insulations is simulated in this study. To simulate charge dynamics inside the insulation, different models have been developed. Conductivity‐based models describe electronic and ionic charges. Such models are structurally simpler than bipolar charge transport models because of their macroscopic description. So far, the macroscopic description is insufficient, as it does not depict the accumulation of homocharges and heterocharges near the electrodes and the transport of charge packets. In this study, a conductivity‐based model is developed to simulate the transport of charges and the formation of homocharges and heterocharges. The conductivity model depends on the electric field and on the temperature. This model is extended by two Gaussian curves, moving from the electrodes to the counter electrodes, which features an increased conductivity in comparison to bulk conductivity. The bulk conductivity is obtained from measurements in the literature. The permittivity is modelled to be non‐constant in the vicinity of the electrodes due to e.g. interdiffusion between the bulk insulation and the semiconducting layer. A comparison between the simulation results and the reference measurements confirms the applicability of the presented approach for the description of the dynamic charge distribution in XLPE cable insulation.
Sensor network node scheduling for preserving coverage of wireless multimedia networks
Authors: Osamy Walid , Khedr Ahmed M. , Salim Ahmed , Agrawal Dharma P.
Published: May 2019

Wireless multimedia sensor networks (WMSNs) are receiving increasing consideration in the deployment of unmanned surveillance systems for applications such as monitoring battle field and security surveillance. However, ensuring high levels of coverage of the monitored area and concurrently maximising the WMSN lifetime remains a challenging issue. The authors introduce a novel distributed algorithm in this study, for scheduling multimedia sensor nodes (MSNs) activity that maximises coverage and minimises energy consumption. The proposed activity scheduling algorithm incorporates an approach that enables each MSN in WMSN to efficiently extract its cover sets to ensure that the critical points are monitored, and thereby minimise and effectively balance the network energy utilisation. They introduce a new way to select the most suitable cover set of an MSN by assigning priority for each cover set based on the correlation of visual information from the camera observations. The efficacy of the proposed approach is studied through rigorous simulations. Their simulation work and results comparison with existing approaches demonstrate that their proposed scheme exceeds current results in terms of network lifetime, capture rate and percentages of dead and active nodes.
Non‐isolated resonant link DC–DC converter for use with GaN devices
Authors: Orr Maria , Finney Stephen , Holliday Derrick
Published: May 2019

As new wide band‐gap (WBG) devices are developed and improved, new topologies and control schemes are required to take advantage of the ultra‐fast switching turn on/off speeds that are now available, without the limitations of switching losses and unacceptable EMI from fast switching transitions. This paper presents a non‐isolated DC–DC resonant link converter that allows for soft switching over an extended load range that is particularly suited to GaN devices.
Experimental comparison of two linear machines developed for the free piston engine
Authors: Baker Nick.J. , Sa Jalal Aslan , Wang Junwan , Korbekandi Ramin M.
Published: May 2019

In this study, a linear synchronous machine is compared with a linear transverse flux machine. Both machines have been designed and built with the intention of being used as the power take off in a free piston engine. As both topologies are cylindrical, it is not possible to construct either using just flat laminations and so alternative methods are described and demonstrated. Despite the difference in topology and specification, the machines are compared on a common base in terms of rated force and suitability for use as a generator. Experience gained during the manufacture of two prototypes is described.
Parallel current‐controlled synchronverters for voltage and frequency regulation in weak grids
Authors: Roldán‐Pérez Javier , Rodríguez‐Cabero Alberto , Prodanovic Milan
Published: May 2019

The emulation of synchronous machines is becoming an attractive solution to provide virtual inertia and voltage support to weak grids and microgrids, representing an alternative to conventional current‐injection control strategies. However, synchronverters operate as voltage sources and this makes it difficult to limit the current when an event like voltage sag takes place. Here, a method to limit the output current of synchronverters in parallel connection is proposed. First of all, a fictitious reference current is generated, and its value is then followed by an internal current controller. A method to avoid the loss of synchronism when the current saturates is proposed and studied in detail. Also, the implementation of the controller is addressed carefully. All the control system improvements are tested on a prototype consisting of two 15 kVA synchronverters connected in parallel to a configurable weak grid.
Green biosynthesis of gold nanoparticles by Lilium casa blanca petals and evaluation of catalytic activity
Authors: Li Haimin , Wang Wenjun , Ang Beijun , Xiong Jianhua , Zhang Fengying , Chen Weiping , Du Juan
Published: May 2019

A simple, fast, and eco‐friendly method for the biosynthesis of gold nanoparticles (AuNPs) using Lilium casa blanca petals as a reducing and protecting agent was reported. The heating time had been shortened to 30 min for biosynthesis of AuNPs, which only took 15 mg Lilium casa blanca petals powder. The biosynthetic AuNPs, which had a uniform particle size distribution, were in spherical with the average size of 5.933 ± 1.158 nm. In addition, the conversion rate of Au3+ to Au0 was quite high. Through the discussion on the nutrients' concentrations before and after the synthesis, it was found that sugars, alkaloids, flavonoids, and proteins were the reducing and stabilising agents. The biosynthetic AuNPs had good catalytic activity, taking the hydroboration of nitrophenol and methylene blue as examples. Catalytic reduction followed pseudo‐first‐order kinetics. Moreover, the apparent rate constant was a linear correlation with the concentrations of AuNPs. The normalised rate constant of the proposed AuNPs was higher than other reported AuNPs, which indicated the excellent catalytic activity. All the results foreshowed the wide range of applications of the biosynthetic AuNPs by Lilium casa blanca petals.
Do star clusters form in a completely mass-segregated way?
Authors: Pavlík Václav , Kroupa Pavel , Šubr Ladislav
Published: May 2019

Context. ALMA observations of the Serpens South star-forming region suggest that stellar protoclusters may be completely mass segregated at birth. Independent observations also suggest that embedded clusters form segregated by mass.

Aims. As the primordial mass segregation seems to be lost over time, we aim to study on which timescale an initially perfectly mass-segregated star cluster becomes indistinguishable from an initially not mass-segregated cluster. As an example, the Orion Nebula Cluster (ONC) is also discussed.

Methods. We used N-body simulations of star clusters with various masses and two different degrees of primordial mass segregation. We analysed their energy redistribution through two-body relaxation to quantify the time when the models agree in terms of mass segregation, which sets in only dynamically in the models that are primordially not mass segregated. A comprehensive cross-matched catalogue combining optical, infrared, and X-ray surveys of ONC members was also compiled and made available.

Results. The models evolve to a similar radial distribution of high-mass stars after the core collapse (about half a median two-body relaxation time, trh) and become observationally indistinguishable from the point of view of mass segregation at time τv ≈ 3.3 trh. In the case of the ONC, using the distribution of high-mass stars, we may not rule out either evolutionary scenario (regardless of whether they are initially mass segregated). When we account for extinction and elongation of the ONC, as reported elsewhere, an initially perfectly mass-segregated state seems to be more consistent with the observed cluster.
Dust trajectory simulations around the Sun, Vega, and Fomalhaut
Authors: Stamm Johann , Czechowski Andrzej , Mann Ingrid , Baumann Carsten , Myrvang Margaretha
Published: May 2019

Context. Vega and Fomalhaut display a thermal emission brightness that could possibly arise from hot dust near the stars, an inner extension of their planetary debris disks. An idea has been suggested that nanometer-sized dust particles are kept in the vicinity of the stars by electromagnetic forces. This resembles the trapping that model calculations show in the corotating magnetic field in the inner heliosphere within approximately 0.2 AU from the Sun.

Aims. The aim of this work is to study whether the trapping of dust due to electromagnetic forces acting on charged dust near the Sun can occur around Vega and Fomalhaut and what are the conditions for trapping.

Methods. We studied the dust trajectories with numerical calculations of the full equation of motion, as well as by using the guiding center approximation. We assumed a constant dust charge and a Parker-type magnetic field, which we estimated for the two stars.

Results. We find no bound trajectories of charged particles around Vega or Fomalhaut as long as the radiation pressure force exceeds the gravitational force, that is, for particles smaller than 1 μm. A trapping zone could exist inside of 0.02 AU for Vega and 0.025 AU for Fomalhaut, but only for those particles with radiation pressure force smaller than gravitational force. In comparison to the Sun, the trapping conditions would occur closer to the stars because their faster rotation leads to a more closely wound-up magnetic field spiral. We also show that plasma corotation can be consistent with trapping. Our model calculations show that the charged particles are accelerated to stellar wind velocity very quickly, pass 1 AU after approximately three days, and are further ejected outward where they pass the debris disks at high velocity. We find this for particles with a surface charge-to-mass ratio larger than 10−6 elementary charges per proton mass for both negatively and positively charged dust and independent of the strength of the radiation pressure force. Based on charging assumptions, this would correspond to dust of sizes 100 nm and smaller.
Transit least-squares survey
Authors: Heller René , Hippke Michael , Rodenbeck Kai
Published: May 2019

The extended Kepler mission (K2) has revealed more than 500 transiting planets in roughly 500 000 stellar light curves. All of these were found either with the box least-squares algorithm or by visual inspection. Here we use our new transit least-squares (TLS) algorithm to search for additional planets around all K2 stars that are currently known to host at least one planet. We discover and statistically validate 17 new planets with radii ranging from about 0.7 Earth radii (R⊕) to roughly 2.2 R⊕ and a median radius of 1.18 R⊕. EPIC 201497682.03, with a radius of 0.692+0.059−0.048, is the second smallest planet ever discovered with K2. The transit signatures of these 17 planets are typically 200 ppm deep (ranging from 100 ppm to 2000 ppm), and their orbital periods extend from about 0.7 d to 34 d with a median value of about 4 d. Fourteen of these 17 systems only had one known planet before, and they now join the growing number of multi-planet systems. Most stars in our sample have subsolar masses and radii. The small planetary radii in our sample are a direct result of the higher signal detection efficiency that TLS has compared to box-fitting algorithms in the shallow-transit regime. Our findings help in populating the period-radius diagram with small planets. Our discovery rate of about 3.7% within the group of previously known K2 systems suggests that TLS can find over 100 additional Earth-sized planets in the data of the Kepler primary mission.
Faunistic patterns and diversity components of leech assemblages in karst springs of Montenegro
Authors: Marinković Nikola , Karadžić Branko , Pešić Vladimir , Gligorović Bogić , Grosser Clemens , Paunović Momir , Nikolić Vera , Raković Maja
Published: May 2019

The aim of this study was to reveal faunistic and diversity patterns and to assess the effects of environmental factors on the differentiation of leech communities. This study covers investigations of 82 karst springs in Montenegro from 2009–2017. The communities were analyzed in respect to five wellspring types – caves, sublacustrine, limnocrene, rheo-limnocrene and rheocrene. The percentage of substrate types and aquatic vegetation cover was recorded alongside water parameters. In total, 18 leech species were identified, of which two were recently described as new species for science (Dina minuoculataGrosser, Moritz and Pešić, 2007 andGlossiphonia balcanicaGrosser and Pešić, 2016).K-means clustering was used to classify leech assemblages into three homogenous groups. The patterns of leech communities and the components of bothalphaandbetadiversity were examined in identified groups of assemblages. The significance of environmental factors and the impact of selected factors were assessed through forward selection analysis, CCA and RDA. Our results indicate that the type of spring and the environmental variables, as well as the combination of biotic and abiotic factors in a microhabitat dictate the distribution of leeches.
Piles in chalk under axial loading
Authors: Doghman Mirna , Mroueh Hussein , Burlon Sébastien
Published: May 2019

Chalk exhibits a viscous behavior depending on time and it presents a noticeable creep under constant load. Consequently, piles founded in chalk media may have their design greatly affected. However, the different standards of the design of deep foundations don’t take into account this viscous behavior and its effect on the pile settlement in the long term. This paper deals with the case of piles under monotonic axial loads in chalk. Two methods of predicting pile settlement are developed: the transfer curves method tz, taking into account the viscosity, and the macroelement technique.
Smart monitoring system for risk management in the underground space
Authors: Shahrour Isam , Bian Hanbing , Xie Xiongyao , Zhang Zixin
Published: May 2019

This paper presents a smart monitoring system for risk management in the underground space. This space has a major role in cities, but it suffers from high vulnerability to hazards such as fire, flood and accidents. The paper provides analysis of the vulnerability of the underground space and shows how a smart monitoring system of human presence, indoor conditions, underground space access and equipment performances with advanced data analysis could help in improving the risk management in this space.
Flexural resistance of the polypropylene fibres reinforced cement mixes with waste material
Authors: Kheir Samer Abou , Wakim Jad , Awwad Elie
Published: May 2019

The polypropylene (PP) fibers in shotcrete has been used for ground support and building strengthening, since several decades. However, the recent trend is to use the waste material in cementbased mixes to produce an eco-friendly material. Such waste material is the incineration fly ash (FA) that is classified as a hazardous product. This study is intended to establish the mechanical properties of fiber reinforced mortar in addition to cement or sand partial replacement by fly ash, in terms of flexural strength testing. The mechanical properties reflect the influence of the dosage of fiber content and the proportion of the fly ash on the flexural strength. The percentage of cement or sand was replaced by 0, 10, 20, and 30% fly ash. The dosage of fibers was 0, 0.6, 1.2, and 1.8 kg/m3. This green mix with fibers provides a partial substitute of cement as it is cheaper, by incorporating waste product, and saving energy consumption in the production. Due to growing interest in sustainable construction, engineers and architects are motivated to choose such materials which are more sustainable.
Construction delay of a penstock
Authors: El Tani Mohamed , Hage Chehade Fadi
Published: May 2019

Uncertainties are not always quantifiable and particularly those that result from a poor management. This is the case of the construction of a penstock of a hydroelectric project. The penstock is an assembly of imbricated cylindrical blocks. The steel blocks deformed during transportation and storage. Plastic deformations and buckling are undesired effects or the blocks have to be replaced. A back analysis was made considering many different transport and storage cases. The case where the blocks were laid on a rigid ground without prevention or protection is examined with an analytic model. This is followed by an analysis of the state of stresses and a validation of the model.
Comparative study of modeling methods used to simulate initial stresses in prestressed beams towards manual analysis
Authors: Al-Ilani Mohamad , Temsah Yehya
Published: May 2019

Numerical modeling of the prestressing element that generates prestressed effect in beams has always been considered a big challenge. This research compares two methods of modeling; In the first method we used initial stresses predefined stress and in the second method we used the temperature strain. Concrete damage plasticity model (CDP) was used to model the non-linear behavior of concrete material and an elasto-plastic behavior was applied to ordinary and prestressed reinforcement. Truss elements were used to model ordinary and prestressed reinforcement embedded inside the concrete. As a result, Initial Temperature load method showed less error in bottom and top stresses and cambering of beam in comparison with the basic concept method, than predefined method.
Sustainable safety evaluation of roads network in case of extreme weather events
Authors: Pucci Alessandro , Puppio Mario Lucio , Giresini Linda , Matos José , Sousa Hélder , Sassu Mauro
Published: May 2019

Recent failures in road networks highlight their vulnerability towards natural hazards, particularly to extreme weather events. This paper proposes a method to evaluate the safety of road networks in case of collapse of one or more bridges. In addition, relevant consequences in terms of safety of human life, direct and indirect cost are crucial aspects to consider. The framework described here is based on the knowledge of road and river network, of the individual bridges and of the traffic data. However, this approach can be generalized in case of interruption of road network due to other causes. An algorithm has been developed to extract traffic data from Google and elaborate it throughout a procedure based on the application of the USA Highway Capacity Manual. This consents to have a quantitative definition of the road traffic directly from the users and to get updated traffic data. The maps are processed throughout a GIS software and, thanks to the application of a routing algorithm and proper constraints, it is possible to evaluate the effects of the interruption of one or more bridges. The consequences are evaluated in terms of drivers’ delay and time cost. This provides useful information about priority of intervention with the aim of proposing to stakeholders a suitable instrument for disaster prevention and management.
Failure risk of recycled aggregates concrete
Authors: Grondin Frédéric , Guo Menghuan , Rozière Emmanuel , Loukili Ahmed
Published: May 2019

In the sustainable development context, the use of demolition waste increases in the building industry. Recycled aggregates from the demolition of concrete structures are then mixed in new concrete. Furthermore, the performance evaluation of a these recycled aggregate concrete (RAC) mix is not only limited to the determination of its conventional mechanical properties. The failure risk of concrete elements in structures made from RAC needs a comprehensive analysis. For that, a study on the fracture process of RAC has been performed and compared with that of normal concrete of the same structural class. Acoustic emission technique and digital correlation method have been used to follow the cracking process. Also, a new modelling approach for the fracture behaviour of RAC at the mesoscopic scale has been developed. It has taken into account the old attached mortar surrounding recycled aggregates. Results show that RAC has a more brittle behaviour than ordinary concrete and the numerical analysis shows that cracks growth through the recycled aggregates which have brittleness behaviour.
Investigation of exhaust gas heat recovery unit for diesel power generator
Authors: Alhajjar Ibrahim , Al Moussawi Houssein , Fardoun Farouk
Published: May 2019

The aim of this paper is to find a proper heat recovery unit that recovers lost energy from a diesel power generator exhaust. This process is performed by inserting the exhaust gas of a 20 kVA power generator into a specifically configured shell & tube exchanger, and transferring its energy into circulating water. The carried energy is then stored in a thermal storage tank so that it would be used for a selected residential energy demand. This method is called “cogeneration”. Different configurations of heat exchanger and tank volumes are considered and flow simulations are performed in order to select a suitable recovery unit for the given design conditions.
Ensuring the sustainability of real-time embedded system under both QoS and Energy Constraints
Authors: Abdallah Maissa , Abdallah Nadine , Chetto Maryline
Published: May 2019

Nowadays, wireless sensor networks (WSNs) are more and more used in applications such as environment monitoring, healthcare monitoring, etc...The challenge in sensor networks is to ensure the sustainability of the system by guaranteeing the required performance level. However, with the limited capacity of finite power sources and the need of guaranteeing a long lifetime of those systems, it is suitable to use energy harvesting which allows to supply low-power electronic systems by converting ambient energy into electric power. Hence, our study is concerned with the problem of soft periodic and aperiodic tasks scheduling in sensor nodes powered by energy harvesters. In this paper, we address this issue by proposing three energy-aware schedulers, namely BG-Green-RTO, BG-Green-BWP and Green-AWP which aim to improve the responsiveness of aperiodic tasks while still guaranteeing the execution of periodic tasks considering their timing and energy constraints. Such algorithms allow to gracefully cope with processing overload and energy starvation. Moreover, a simulation study permits to show their performance.
Operating Room Management System: Patient Programming.
Authors: Bilal BOU SALEH , Abdellah EL MOUDNI , Lina CHAHAL , Oussama BARAKAT , Ghazi BOU SALEH
Published: May 2019

The Operating Theater (OT) is one of the most critical and expensive hospital resources since a high percentage of hospitalizations are due to surgery. The main objectives are to perform the operation at the right time without incurring excessive waiting times and to optimize the use of medical resources in order to achieve maximum profitability. Management problems in the (OT) have been identified with well-known problems in the field of manufacturing or transport. This prompted us to look for a model used in industrial applications that would allow us to solve the problems of (OT) process as a whole.

We first present the hybrid architectural concepts and the development of the control system for the management of the operating room process in its entirety. We then describe the patient programming function and the associated module algorithm based on distributed artificial intelligence.
Different applications of RRE on nonsymmetric algebraic Riccati equation in transport theory
Authors: El Moallem Rola , Sadok Hassane
Published: May 2019

This paper proposes three different ways of applying a vector extrapolation method to a slow converging vector sequence to accelerate the convergence. The solution of this vector sequence is used to solve an algebraic Riccati equation in transport theory. A numerical example is presented to compare the three applications.
The analytic study on the heavy steel plate snake rolling with the different roll diameters
Authors: Meng Qing-cheng , Jiang Lian-yun , Ma Li-feng , Lei Jun-yi
Published: May 2019

The deformation in the inner region along the thickness of the heavy steel plate can be improved by snake rolling method. Then the microstructure and property will be refined and the crack in the inner region may be avoided. So the in-depth research on snake rolling method mechanics parameter modeling should be conducted to guide production. The rolling deformation zone will be divided into back slip zone, cross shear zone, front slip zone and reverse deflection zone according to the direction of the friction during the snake rolling process. The four zones may not exist at the same time. The boundary conditions of existence of the back slip zone, cross shear zone and front slip zone were established by calculating the position of neutral point by a special method. The calculating models which were used to calculate the snake rolling mechanical parameters including the rolling force and rolling torque were setup. The calculated models of unit compressive pressure in the four zones were setup by the slab method, and at this basis, the accurate calculating models of the rolling force and rolling torque were setup according to the composition of the rolling deformation zone and the boundary condition. The mechanical parameters were calculated by the analytic method and the numerical method, and the relative deviation is less than 5% which can satisfy the industrial requirement. The present analytical model can predict the characteristics during snake rolling easily and quickly and it is also suitable for online control applications.
A flexible electromagnetic control technique for interference adjustment in large-size sleeved backup rolls
Authors: Feng Yanfeng , Liu Wenwen , Yang Tingsong , Du Fengshan , Sun Jingna
Published: May 2019

Large-size sleeved backup rolls including the roll core and roll shell play a crucial role of supporting work rolls in the precision-rolling process. However, since the backup roll endures an unavoidable periodic force during the rolling process, the interference between its roll shell and roll core is correspondingly reduced, which leads to rolled strip defects or a decreased service life of the roll. To solve this problem, an interference electromagnetic control technique (IECT) was proposed for large-size sleeved backup rolls to freely regulate contact pressure between the roll core and roll shell using a thermally driven electromagnetic stick mounted inside the roll core, thereby adjusting the interference for large-size sleeved backup rolls. In this study, a finite element method (FEM) simulation of a ϕ1400 × 1420 mm size sleeved backup roll was built to demonstrate the effect of this technique by analysing contact pressure variations and roll profile curves of the backup roll at various heating times. According to the FEM model, the key parameters of the IECT including frequency and current density were optimized based on the simulation results. Compared with the conventional rolling process, the electromagnetic control method on the interference adjustment of the large-size sleeved backup roll is shown to be a possible alternative for a better strip shape with a much longer service life.
Leaching behavior and kinetics of vanadium extraction from vanadium-bearing steel slag
Authors: Gao Minglei , Xue Xiangxin , Li Lanjie , Yang He , Chen Donghui
Published: May 2019

The vanadium-bearing steel slag as solid waste is also one of valuable vanadium-containing resource. Recovering vanadium from the refractory steel slag is a great challenge in the world. A leaching process study using high concentration sodium hydroxide solution was proposed in this laboratory work. The effects of sodium hydroxide concentration, particle size, leaching temperature and the ratio of alkali to slag on the rate of vanadium leaching were determined and the leaching kinetics was presented. It indicates that the leaching rate is highly sensitive to the sodium hydroxide concentration and leaching temperature and increases with increasing temperature and sodium hydroxide concentration. By studying the reaction mechanisms, it was found that the dicalcium silicate, tricalcium silicate and calcium ferrited which co-exist with calcium vanadate in the vanadium-bearing steel slag were gradually exposed and reacted with NaOH media to form Na3VO4. The leaching kinetics was analyzed which indicated that the leaching rate is controlled by the chemical reaction with the apparent activation energy of 51.34 kJ/mol. On the basis of this process, the vanadium can be effectively extracted with a leaching rate of more than 80%. The leaching medium can be recycled. It is an effective and cleaner process for leaching vanadium.
Régulation des menaces inhérentes aux activités physiques et sportives et construction des attitudes interpersonnelles et intergroupes : revue théorique et perspectives
Authors: Rull Marion , Margas Nicolas
Published: May 2019

L’engagement corporel inhérent aux activités physiques, sportives et artistiques (APSA) implique des menaces physiques et symboliques que les pratiquants doivent réguler. Ces régulations émotionnelles modifient leurs attitudes interpersonnelles et intergroupes et, par là même, leurs comportements vis-à-vis des autres individus et groupes pendant la pratique mais aussi ailleurs et plus tard. Au regard de l’enjeu que représentent ces attitudes pour les différents terrains sportifs (e.g., cohésion, entraide, agressivité, coping en compétition, inclusion sociale et citoyenneté en éducation physique et sportive et en activités physiques adaptées), nous proposons une revue des modèles théoriques en psychologie sociale qui identifient les processus d’influence des menaces sur les attitudes interpersonnelles et intergroupes. Nous distinguons trois types de menace présentes dans la pratique des APSA, soit les menaces interpersonnelles, intergroupes et du contexte, et situons la portée des modèles associés à ces menaces pour les terrains des APSA. Malgré la pertinence de ces modèles pour comprendre la construction des attitudes interpersonnelles et intergroupes au cours des APSA, leur utilisation apparaît marginale en sciences du sport. Notre revue ouvre donc sur des perspectives d’intervention innovantes et des propositions d’articulation des modèles présentés avec ceux majoritairement utilisés en sciences du sport.
The Role of Diagnostic Hysteroscopy in the Evaluation of Fallopian Tube Patency: a Short Review
Authors: Hager Marlene , Simek Inga Malin , Promberger Regina , Ott Johannes
Published: May 2019

The relevance of diagnostic hysteroscopy, especially when performed in an outpatient “office” setting, in the evaluation process of infertility has increased within the last few years. Notably, several articles on a possible role for diagnostic hysteroscopy in the assessment of Fallopian tube patency have been published recently. Three relevant articles were identified. Visualizing a “flow effect” or air bubbles dispersing through the ostia, sonographically assessed shifts in cul de sac volume, and selective Fallopian tubal cannulation are reportedly promising hysteroscopic techniques. In this review, an overview of hysteroscopy, details about diagnostic reliability, and considerations with regard to ease of use and difficulties are summarized. Based on these articles, hysteroscopic evaluation of tubal patency seems to be a promising, clinically relevant field for future clinical research.
Axillary surgery in breast cancer patients treated with breast-conserving surgery at german breast cancer centers within the last 14 years – comparison of a university center and a community hospital
Authors: de Gregorio Amelie , Widschwendter Peter , Albrecht Susanne , de Gregorio Nikolaus , Friedl Thomas , Huober Jens , Janni Wolfgang , Ebner Florian
Published: May 2019

Background Guideline recommendations for axillary surgical approach in breast cancer (BC) treatment changed over the last decade.

Methods Data from all invasive BC patients (n = 5344) treated with breast conserving surgery (BCS) at the breast cancer centers of the University Hospital Ulm (U‑BCC) and the community hospital Dachau (D‑BCC) were included into a retrospective analysis for assessing information on axillary surgery between 2003 and 2016 based on the documented cancer registry data.

Results The average annual rate of sentinel node biopsy (SNB) was 85.5 % and 87.2 % in Ulm and Dachau, respectively. SNB was performed more precisely at the U‑BCC with a median of 2.4 resected lymph nodes (LN) compared to a median of 3.2 resected LN in Dachau. Median number of resected LN for axillary lymph node dissection (ALNE) showed a statistically significant reduction over time in Ulm (rs = − 0.82; p < 0.001) and Dachau (rs = − 0.76; p = 0.002). The rate of secondary ALNE (after SNB; 2° ALNE) decreased significantly in U‑BCC (rs = − 0.76; p = 0.002) while it remained stable in D‑BCC. The influential publication of the Z0011 study in 2010 resulted in a significant reduction of secondary ALNE (24.1 % pre Z0011 and 14.4 % postZ0011; p < 0.001) in Ulm.

Conclusion Changes in axillary surgery over time can be seen in the annual statistics of the reviewed BCCs. With BCS, mostly SNB was performed and numbers of removed LN in ALNE have decreased. In the U‑BCC, the rate of 2° ALNE dropped after the publication of the Z0011 data. The fact that no such decrease for 2° ALNE was found in D‑BCC suggests that university hospitals implement new data and research results into clinical routine earlier than peripheral community hospitals.
Internalization theory for the digital economy
Authors: Banalieva Elitsa R , Dhanaraj Charles
Published: May 2019

We study the internationalization of digital service multinational enterprises (SMNCs), focusing on how digitalization alters internalization theory’s assumptions about the nature of firm-specific assets (FSAs) and the theory’s predictions about governance choices in cross-border transactions. We invoke Simon’s (Proc Am Philos Soc 106(6):467–482, 1962) near-decomposability concept to explain how digitalization enables two distinct types of FSAs – technology and human capital. Applying the ideas of modularity and skill complexity, we further distinguish between core versus peripheral technology FSAs and between generic versus advanced human capital FSAs. Building on the transferability and appropriability of these strategic assets, we theorize on the FSAs’ internalization propensity in the digital age. We propose that with rising digitalization, the network plays a dual role – as a governance mode and as a strategic resource. Integrating insights from network economics, particularly increasing returns to scale, we propose that network advantages (On) emerge as a distinct strategic resource that merits separate investigation from the traditional asset-based (Oa) and transaction-based (Ot) advantages.
2D simulation of the electromagnetic wave across the non-uniform reentry plasma sheath with COMSOL
Authors: Zhang Jiahui , Liu Yanming , Li Xiaoping , Shi Lei , Yang Min , Bai Bowen
Published: May 2019

The simulation of the electromagnetic wave propagation plays an important role in solving the communication blackout issue. Finite element analysis software package COMSOL is employed by us to model the electromagnetic wave propagation in the presence of the non-uniform reentry plasma sheath in this paper. The propagation characteristics of the electromagnetic wave are analyzed by the observation of the field distributions. The electromagnetic wave with s polarization begins to attenuate as an exponential function at the cut-off position. The mode conversion takes place for the p polarization wave when the real part of the plasma permittivity is close to 0. The wave reflection, transmission, and absorption coefficients as a function of the frequency are calculated and analyzed. The absolute agreements between the results calculated by COMSOL model and by the layered model are achieved. The difference of the coefficients between s and p polarization waves can be explained by the presence or absence of the mode conversion. Conclusions in this paper can be the foundation to employ the COMSOL to study the interactions between the electromagnetic wave and the plasma.