bluuebunny/crossref_metadata_2025_split huggingface dataset:
OGLE-2016-BLG-0263Lb: Microlensing Detection of a Very Low-mass Binary Companion through a Repeating Event Channel
Authors: Han C. , Udalski A. , Gould A. , Bond I. A. ,   and, Albrow M. D. , Chung S.-J. , Jung Y. K. , Ryu Y.-H. , Shin I.-G. , Yee J. C. , Zhu W. , Cha S.-M. , Kim S.-L. , Kim D.-J. , Lee C.-U. , Lee Y. , Park B.-G. ,   (The KMTNet Collaboration), Skowron J. , Mróz P. , Pietrukowicz P. , Kozłowski S. , Poleski R. , Szymański M. K. , Soszyński I. , Ulaczyk K. , Pawlak M. ,   (The OGLE Collaboration), Abe F. , Asakura Y. , Barry R. , Bennett D. P. , Bhattacharya A. , Donachie M. , Evans P. , Fukui A. , Hirao Y. , Itow Y. , Koshimoto N. , Li M. C. A. , Ling C. H. , Masuda K. , Matsubara Y. , Muraki Y. , Nagakane M. , Ohnishi K. , Ranc C. , Rattenbury N. J. , Saito To. , Sharan A. , Sullivan D. J. , Sumi T. , Suzuki D. , Tristram P. J. , Yamada T. , Yamada T. , Yonehara A. ,   (The MOA Collaboration)
Published: September 2017

Abstract
We report the discovery of a planet-mass companion to the microlens OGLE-2016-BLG-0263L. Unlike most low-mass companions that were detected through perturbations to the smooth and symmetric light curves produced by the primary, the companion was discovered through the channel of a repeating event, in which the companion itself produced its own single-mass light curve after the event produced by the primary had ended. Thanks to the continuous coverage of the second peak by high-cadence surveys, the possibility of the repeating nature due to source binarity is excluded with a 96% confidence level. The mass of the companion estimated by a Bayesian analysis is

. The projected primary-companion separation is

au. The ratio of the separation to the snow-line distance of

corresponds to the region beyond Neptune, the outermost planet of the solar system. We discuss the importance of high-cadence surveys in expanding the range of microlensing detections of low-mass companions and future space-based microlensing surveys.
Where are the Binaries? Results of a Long-term Search for Radial Velocity Binaries in Proto-planetary Nebulae
Authors: Hrivnak Bruce J. , Steene Griet Van de , Winckel Hans Van , Sperauskas Julius , Bohlender David , Lu Wenxian 
Published: September 2017

Abstract
We present the results of an expanded, long-term radial velocity search (25 years) for evidence of binarity in a sample of seven bright proto-planetary nebulae (PPNe). The goal is to investigate the widely held view that the bipolar or point-symmetric shapes of planetary nebulae (PNe) and PPNe are due to binary interactions. Observations from three observatories were combined from 2007 to 2015 to search for variations on the order of a few years and then combined with earlier observations from 1991 to 1995 to search for variations on the order of decades. All seven show velocity variations due to periodic pulsation in the range of 35–135 days. However, in only one PPN, IRAS 22272+5435, did we find even marginal evidence for multi-year variations that might be due to a binary companion. This object shows marginally significant evidence of a two-year period of low semi-amplitude, which could be due to a low-mass companion, and it also displays some evidence of a much longer period of >30 years. The absence of evidence in the other six objects for long-period radial velocity variations due to a binary companion sets significant constraints on the properties of any undetected binary companions: they must be of low mass, ≤0.2 M
⊙, or long period, >30 years. Thus the present observations do not provide direct support for the binary hypothesis to explain the shapes of PNe and PPNe and severely constrains the properties of any such undetected companions.
How Does the Shape of the Stellar Spectrum Affect the Raman Scattering Features in the Albedo of Exoplanets?
Authors: Oklopčić Antonija , Hirata Christopher M. , Heng Kevin 
Published: September 2017

Abstract
The diagnostic potential of the spectral signatures of Raman scattering, imprinted in planetary albedo spectra at short optical wavelengths, has been demonstrated in research on planets in the solar system, and has recently been proposed as a probe of exoplanet atmospheres, complementary to albedo studies at longer wavelengths. Spectral features caused by Raman scattering offer insight into the properties of planetary atmospheres, such as the atmospheric depth, composition, and temperature, as well as the possibility of detecting and spectroscopically identifying spectrally inactive species, such as H2 and N2, in the visible wavelength range. Raman albedo features, however, depend on both the properties of the atmosphere and the shape of the incident stellar spectrum. Identical planetary atmospheres can produce very different albedo spectra depending on the spectral properties of the host star. Here we present a set of geometric albedo spectra calculated for atmospheres with H2/He, N2, and CO2 composition, irradiated by different stellar types ranging from late A to late K stars. Prominent albedo features caused by Raman scattering appear at different wavelengths for different types of host stars. We investigate how absorption due to the alkali elements sodium and potassium may affect the intensity of Raman features, and we discuss the preferred strategies for detecting Raman features in future observations.
The Relation between Cosmological Redshift and Scale Factor for Photons
Authors: Tian Shuxun 
Published: September 2017

Abstract
The cosmological constant problem has become one of the most important ones in modern cosmology. In this paper, we try to construct a model that can avoid the cosmological constant problem and have the potential to explain the apparent late-time accelerating expansion of the universe in both luminosity distance and angular diameter distance measurement channels. In our model, the core is to modify the relation between cosmological redshift and scale factor for photons. We point out three ways to test our hypothesis: the supernova time dilation; the gravitational waves and its electromagnetic counterparts emitted by the binary neutron star systems; and the Sandage–Loeb effect. All of this method is feasible now or in the near future.
La forge gauloise de la nation
Authors: Bourdon Étienne 
Published: September 2017

L’expression « nos ancêtres les Gaulois » a longtemps eu vocation à dire, sans contestation possible, les origines de la nation française. Ce roman national commençait par un lever de rideau qui présentait ces lointains ancêtres, intelligents mais bagarreurs, joyeux mais buveurs, braves mais désunis, glorieux mais vaincus. Au-delà de son illusoire évidence, l’expression pose de nombreux problèmes historiques et épistémologiques. Cette fabrique des ancêtres révèle une conception particulière de l’identité et de la nation par un usage politique, moral et éducatif de l’histoire. Le grand historien Ernest Lavisse en est un des forgerons par ses écrits universitaires et ses célèbres manuels scolaires, les Petits Lavisse. Car il s’agit bien de faire la nation, et c’est à l’école qu’elle se forge. Il faut donc s’intéresser au façonnage de « nos ancêtres les Gaulois », aux choix et aux silences des discours scientifiques et scolaires, en les replaçant au cœur des débats archéologiques, historiques et politiques du demi-siècle lavissien (1876-1922). Instituteur de la République, Ernest Lavisse a forgé de sa plume, par l’écriture historique, une conception nationale du Gaulois, l’un des personnages majeurs dont la IIIe République naissante avait besoin. Cette histoire des savoirs montre que les propos historiques sur les origines antiques de la nation se révèlent être un discours sur le présent, qui prend la voix du passé.
Periodic Solutions of Second Order Degenerate Differential Equations with Delay in Banach Spaces
Authors: Bu Shangquan , Cai Gang 
Published: September 2017

AbstractWe give necessary and sufficient conditions of the Lp-well-posedness (resp. -wellposedness) for the second order degenerate differential equation with finite delayswith periodic boundary conditions (Mu)(0) = (Mu)(2π), (Mu)′ (0) = (Mu)′ (2π), where A, B, and M are closed linear operators on a complex Banach space X satisfying D(A) ∩ D(B) ⊂ D(M), F and G are bounded linear operators from into X.
Primary breakup of liquids using a high-speed rotary bell atomizer for spray painting processes
Authors: Shen Bo , Ye Qiaoyan , Tiedje Oliver , Domnick Joachim 
Published: September 2017

The present contribution deals with numerical studies of the primary liquid breakup process using a commercialhigh-speed rotary bell atomizer. The first part of the investigations focuses on the film formation on the distributor disk and the inner surface of the rotary bell. Numerical simulations using the volume of fluid (VOF) approach were carried out. A non-Newtonian liquid is used to investigate the effect of the viscosity on the initial wetting, the film formation process and the film thickness distribution on the bell. The Herschel-Bulkley model is considered to describe the shear-thinning (pseudoplastic) behavior of the fluid. A non-homogeneous film structure is found on the inside surface of the rotary bell. This is also observed in experimental investigations using a high-speed camera.The following disintegration process is studied by applying an appropriately fine computational mesh. The VOF method and Reynolds stress model are used to calculate the disintegration process and the two-phase flow field.The numerical results are compared with images which are recorded by means of a high-speed camera.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4611
Analytical / Computational Approach to Liquid Spray Heating and Vaporization at Supercritical Pressures
Authors: Sirignano William A , Jorda Juanos Albert 
Published: September 2017

Our findings from two areas of background research will define an approach to the study of liquid spray heating andvaporization in gases at supercritical pressure: (i) vaporizing droplets at supercritical pressure and (ii) supercritical combustion in simple configurations, e.g., counterflow. The a priori conclusion that only one phase exists at super- critical pressure is based on false “lore” and not physical law. The question about the phases must be left open until the analysis reaches a conclusion; a proper approach will be defined. Proper equations of state for density and en- thalpy and the determination of phase equilibrium, liquid composition due to dissolved gas, energy of vaporization, surface tension, and transport properties for high pressures will be discussed. The case of an isolated droplet will be reviewed and origin of the transcritical concept will be explained. A counterflow spray configuration at pressures above the liquid critical pressure will be analyzed. The concept of shifting phase equilibrium will be applied as the droplets in the spray heat. Hydrocarbon liquids and oxidizing gaseous environments will be studied. Differences between real fluids and ideal fluids at high pressures will be emphasized. Proper rules for gaseous mixtures andliquid solutions will be discussed.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4615
A quantitative analysis of nozzle surface bound fuel for diesel injectors
Authors: Turner Jack , Sykes Dan , De Sercey Guillaume , Stetsyuk Viacheslav , Gold Martin , Pearson Richard , Crua Cyril 
Published: September 2017

In a fuel injector at the end of the injection, the needle descent and the rapid pressure drop in the nozzle leads todischarge of large, slow-moving liquid structures. This unwanted discharge is often referred as fuel ‘dribble’ and results in near-nozzle surface wetting, creating fuel-rich regions that are believed to contribute to unburnt hydrocarbon emissions. Subsequent fluid overspill occurs during the pressure drop in the expansion stroke when residual fluid inside the nozzle is displaced by the expansion of trapped gases as the pressure through the orifices is equalised, leading to further surface wetting. There have been several recent advancements in the characterisation of these near nozzle fluid processes, yet there is a lack of quantitative data relating the operating conditions and hardware parameters to the quantity of overspill and surface-bound fuel. In this study, methods for quantifying nozzle tip wetting after the end of injection were developed, to gain a better understanding of the underlying processes and to study the influence of engine operating conditions. A high-speed camera with a long- distance microscope was used to visualise fluid behaviour at the microscopic scale during, and after, the end of injection. In order to measure the nozzle tip temperature, a production injector was used which was instrumented with a type K thermocouple near one of the orifices. Image post-processing techniques were developed to track both the initial fuel coverage area on the nozzle surface, as well as the temporal evolution and spreading rate of surface-bound fluid. The conclusion presents an analysis of the area of fuel coverage and the rate of spreading and how these depend on injection pressure, in-cylinder pressure and in-cylinder temperature. It was observed that for this VCO injector, the rate of spreading correlates with the initial area of fuel coverage measured after the end of injection, suggesting that the main mechanism for nozzle wetting is through the impingement of dribble onto the nozzle. However, occasional observations of the expansion of orifice-trapped gas were made that lead to asignificant increase in nozzle wetting.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4661
A new approach to modelling the two way coupling for momentum transfer in a hollow-cone spray
Authors: Papoutsakis Andreas , Sazhin Sergei , Begg Steven , Danaila Ionut , Luddens Francky 
Published: September 2017

A new approach to modelling the interaction between droplets and the carrier phase is suggested. The new model isapplied to the analysis of a spray injected into a chamber of quiescent air, using an Eulerian-Lagrangian approach. The conservative formulation of the equations for mass, momentum and energy transport is used for the analysis of the carrier phase. The dispersed phase is modelled using the Lagrangian approach with droplets represented by individual parcels.The implementation of the Discontinuous Galerkin method (ForestDG), based on a topological representation of the computational mesh by a hierarchical structure consisting of oct- quad- and binary trees, is used in our analysis. Adaptive mesh refinement (h-refinement) enables us to increase the spatial resolution for the computational mesh in the vicinity of the points of interest such as interfaces, geometrical features, or flow discontinuities. The local increase in the expansion order (p-refinement) at areas of high strain rates or vorticity magnitude results in an increase of the order of the accuracy of discretisation of shear layers and vortices.The initial domain consists of a graph of unitarian-trees representing hexahedral, prismatic and tetrahedral elements. The ancestral elements of the mesh can be split into self-similar elements allowing each tree to grow branches to an arbitrary level of refinement. The connectivity of the elements, their genealogy and their partitioning are described by linked lists of pointers. These are attached to the tree data structure which facilitates the on-the-fly splitting, merging and repartitioning of the computational mesh by rearranging the links of each node of the tree. This enables us to refine the computational mesh in the vicinity of the droplet parcels aiming to accurately resolve the coupling betweenthe two phases.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4671
Where does the drop size distribution come from?
Authors: Canu Romain , Dumouchel Christophe , Duret Benjamin , Essadki Mohamed , Massot Marc , Ménard Thibault , Puggelli Stefano , Reveillon Julien , Demoulin François-Xavier 
Published: September 2017

This study employs DNS of two-phase flows to enhance primary atomization understanding and modelling to beused in numerical simulation in RANS or LES framework. In particular, the work has been aimed at improving the information on the liquid-gas interface evolution available inside the Eulerian-Lagrangian Spray Atomization (ELSA) framework. Even though this approach has been successful to describe the complete liquid atomization process from the primary region to the dilute spray, major improvements are expected on the establishment of the drop size distribution (DSD). Indeed, the DSD is easily defined once the spray is formed, but its appearance and even the mathematical framework to describe its creation during the initial breakup of the continuous liquid phase in a set of individual liquid parcels is missing. This is the main aim of the present work to review proposals to achieve a continuous description of the DSD formation during the atomization process.The attention is here focused on the extraction from DNS data of the behaviour of geometrical variable of the liquid- gas interface, such as the mean and Gauss surface curvatures. A DNS database on curvature evolution has been generated. A Rayleigh-Plateau instability along a column of liquid is considered to analyse and to verify the capabilities of the code in correctly predicting the curvature distribution. A statistical analysis on the curvatures data, in terms of probability density function, was performed in order to determine the physical parameters that control the curvatures on this test case. Two different methods are presented to compute the curvature distribution and in addition, the probability to be at a given distance of the interface is studied. This approach finally links the new toolsproposed to follow the formation of the spray with the pioneering work done on scale distribution analysis.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4706
An Experimental Study of Diesel Spray Impingement on a Flat Plate: Effects of Injection Conditions
Authors: Zhu Xiucheng , Zhao Le , Zhao Zhihao , Ahuja Nitisha , Naber Jeffrey , Lee Seong-Young 
Published: September 2017

Advanced injection strategies for internal combustion engines have been extensively studied although there stillexists a significant fundamental knowledge gap on the mechanism for high-pressure spray interaction with the piston surface and chamber wall in the internal combustion engine. The current study focuses on providing qualitative and quantitative information on spray-wall impingement and its characteristics by expanding the range of operating parameters under engine-like conditions. Parameters considered in the experiment are ambient gas and fuel injection conditions. The test included the non-vaporizing spray at the different ambient density (14.8, 22.8 and 30 kg/m3) and injection pressure (1200, 1500 and 1800 bar) with the isothermal condition (ambient, and plate temperatures of 423 K). The test was conducted in the constant-volume vessel with the 60-degree impinging spray angle relative to the plate. The free spray and impinged spray properties were qualitatively analysed based on Mie and schlieren images. The results showed that the lower ambient density and higher injection pressure tended to result in relatively higher impinged spray height. The expanding shape of the impinged spray on the wall showedthe oval shape.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4733
Maximum entropy method for biodiesel spray droplet distribution
Authors: Kolodnytska Ruslana , Skurativskyi Sergiy , Moskvin Pavel 
Published: September 2017

The efficiency of combustion process in diesel engine depends on the spray characteristics. The most importantof them are droplet size and velocity distributions. There are four methods which are used for describing the droplet size distributions: empirical, maximum entropy formalism (MEF), discrete probability function (DPF) and stochastic method. The MEF assumes that spray formation is a random process that can be described using the principle of maximum entropy. DPF method is a combination of random and non-random processes when the drop-size distribution appears from fluctuations in the initial conditions. Under the DPF approach the spray formation is divided into following steps: liquid breakup, ligaments separation, breakup of ligaments into fragments, fragment breakup into droplets. The stochastic breakup model assumes that the probability of formation of daughter droplet breakup size is independent of its parent size (a fractal scaling of breakup has been identified). This paper presents an investigation into the application of MEF model for distribution of biodiesel droplets. We used the model approach with the constraints: normalization, mass conservation, momentum conservation and surface energy conservation. The resulting probability density function (PDF) for velocity and droplet size is obtained by maximizing the Shannon entropy. We also used the new numerical algorithm to improve the model accuracy. The PDF for droplets diameters with different Weber numbers were calculated for both diesel and biodiesel fuels. The MEF predictions were compared against the experimental data for diesel and biodiesel droplet distribution with different injection pressure. According to the maximum entropy method, the influence of fuel thermodynamic properties on the parameters of drop-size and velocity distribution function forfuel sprays has been analysed.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4769
Effect of Prefilmer Edge Thickness on Breakup Phenomena of Liquid Film in Prefilming Airblast Atomizer
Authors: Okabe Takahiro , Katagata Naoki , Sakaki Toshihiro , Inamura Takao , Fumoto Koji 
Published: September 2017

This paper describes the investigation of the effect of a prefilmer edge thickness on the breakup phenomena of aliquid film in a prefilmer airblast atomizer. The breakup phenomena of the liquid film at five prefilmer edge thicknesses (160, 500, 1250, 2000, and 3000 μm) under various conditions was observed using a high-speed camera. The breakup length of the liquid film was calculated by an image processing technique developed in this study. In order to quantitatively evaluate the effect of the prefilmer edge thickness on the breakup frequency, the Fast Fourier Transformation (FFT) analysis was conducted based on the time evolution of the breakup length. The results indicated that the breakup length increase and the breakup frequency decreases by increasing prefilmer edge thickness due to a larger volume of a liquid accumulation attaching to the prefilmer edge. The FFT analysis showed that the increase in prefilmer edge thickness causes the transition of the maximal power spectrum to a lower frequency (i.e. less than 100 Hz) due to the increase in the liquid accumulation at the edge as well. Finally, adimensionless correlation has been proposed for the breakup length of a liquid film.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4931