bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical Calculation of D- and Q-axis Inductance for Interior Permanent Magnet Motors Based on Winding Function Theory
Authors: Liang Peixin , Pei Yulong , Chai Feng , Zhao Kui
Published: July 2016

Interior permanent magnet (IPM) motors are widely used in electric vehicles (EVs), benefiting from the excellent advantages of a more rational use of energy. For further improvement of energy utilization, this paper presents an analytical method of d- and q-axis inductance calculation for IPM motors with V-shaped rotor in no-load condition. A lumped parameter magnetic circuit model (LPMCM) is adopted to investigate the saturation and nonlinearity of the bridge. Taking into account the influence of magnetic field distribution on inductance, the winding function theory (WFT) is employed to accurately calculate the armature reaction airgap magnetic field and d- and q-axis inductances. The validity of the analytical technique is verified by the finite element method (FEM).
Applying Least Absolute Shrinkage Selection Operator and Akaike Information Criterion Analysis to Find the Best Multiple Linear Regression Models between Climate Indices and Components of Cow’s Milk
Authors: Marami Milani Mohammad , Hense Andreas , Rahmani Elham , Ploeger Angelika
Published: July 2016

This study focuses on multiple linear regression models relating six climate indices (temperature humidity THI, environmental stress ESI, equivalent temperature index ETI, heat load HLI, modified HLI (HLI new), and respiratory rate predictor RRP) with three main components of cow’s milk (yield, fat, and protein) for cows in Iran. The least absolute shrinkage selection operator (LASSO) and the Akaike information criterion (AIC) techniques are applied to select the best model for milk predictands with the smallest number of climate predictors. Uncertainty estimation is employed by applying bootstrapping through resampling. Cross validation is used to avoid over-fitting. Climatic parameters are calculated from the NASA-MERRA global atmospheric reanalysis. Milk data for the months from April to September, 2002 to 2010 are used. The best linear regression models are found in spring between milk yield as the predictand and THI, ESI, ETI, HLI, and RRP as predictors with p-value < 0.001 and R2 (0.50, 0.49) respectively. In summer, milk yield with independent variables of THI, ETI, and ESI show the highest relation (p-value < 0.001) with R2 (0.69). For fat and protein the results are only marginal. This method is suggested for the impact studies of climate variability/change on agriculture and food science fields when short-time series or data with large uncertainty are available.
Potential Harmful Effects of PM2.5 on Occurrence and Progression of Acute Coronary Syndrome: Epidemiology, Mechanisms, and Prevention Measures
Authors: Meng Xu , Zhang Ying , Yang Kun-Qi , Yang Yan-Kun , Zhou Xian-Liang
Published: July 2016

The harmful effects of particulate matter with an aerodynamic diameter of <2.5 µm (PM2.5) and its association with acute coronary syndrome (ACS) has gained increased attention in recent years. Significant associations between PM2.5 and ACS have been found in most studies, although sometimes only observed in specific subgroups. PM2.5-induced detrimental effects and ACS arise through multiple mechanisms, including endothelial injury, an enhanced inflammatory response, oxidative stress, autonomic dysfunction, and mitochondria damage as well as genotoxic effects. These effects can lead to a series of physiopathological changes including coronary artery atherosclerosis, hypertension, an imbalance between energy supply and demand to heart tissue, and a systemic hypercoagulable state. Effective strategies to prevent the harmful effects of PM2.5 include reducing pollution sources of PM2.5 and population exposure to PM2.5, and governments and organizations publicizing the harmful effects of PM2.5 and establishing air quality standards for PM2.5. PM2.5 exposure is a significant risk factor for ACS, and effective strategies with which to prevent both susceptible and healthy populations from an increased risk for ACS have important clinical significance in the prevention and treatment of ACS.
Spatiotemporal Interpolation Methods for the Application of Estimating Population Exposure to Fine Particulate Matter in the Contiguous U.S. and a Real-Time Web Application
Authors: Li Lixin , Zhou Xiaolu , Kalo Marc , Piltner Reinhard
Published: July 2016

Appropriate spatiotemporal interpolation is critical to the assessment of relationships between environmental exposures and health outcomes. A powerful assessment of human exposure to environmental agents would incorporate spatial and temporal dimensions simultaneously. This paper compares shape function (SF)-based and inverse distance weighting (IDW)-based spatiotemporal interpolation methods on a data set of PM2.5 data in the contiguous U.S. Particle pollution, also known as particulate matter (PM), is composed of microscopic solids or liquid droplets that are so small that they can get deep into the lungs and cause serious health problems. PM2.5 refers to particles with a mean aerodynamic diameter less than or equal to 2.5 micrometers. Based on the error statistics results of k-fold cross validation, the SF-based method performed better overall than the IDW-based method. The interpolation results generated by the SF-based method are combined with population data to estimate the population exposure to PM2.5 in the contiguous U.S. We investigated the seasonal variations, identified areas where annual and daily PM2.5 were above the standards, and calculated the population size in these areas. Finally, a web application is developed to interpolate and visualize in real time the spatiotemporal variation of ambient air pollution across the contiguous U.S. using air pollution data from the U.S. Environmental Protection Agency (EPA)’s AirNow program.
Improved Biogeography-Based Optimization Based on Affinity Propagation
Authors: Wang Zhihao , Liu Peiyu , Ren Min , Yang Yuzhen , Tian Xiaoyan
Published: July 2016

To improve the search ability of biogeography-based optimization (BBO), this work proposed an improved biogeography-based optimization based on Affinity Propagation. We introduced the Memetic framework to the BBO algorithm, and used the simulated annealing algorithm as the local search strategy. MBBO enhanced the exploration with the Affinity Propagation strategy to improve the transfer operation of the BBO algorithm. In this work, the MBBO algorithm was applied to IEEE Congress on Evolutionary Computation (CEC) 2015 benchmarks optimization problems to conduct analytic comparison with the first three winners of the CEC 2015 competition. The results show that the MBBO algorithm enhances the exploration, exploitation, convergence speed and solution accuracy and can emerge as the best solution-providing algorithm among the competing algorithms.
Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives
Authors: Shi Shih-Chen , Su Chieh-Chang
Published: July 2016

The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose phthalate (HPMCP), and hydroxypropyl methylcellulose acetate succinate (HPMCAS) film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.
Carbon Nanomaterials as Antibacterial Colloids
Authors: Maas Michael
Published: July 2016

Carbon nanomaterials like graphene, carbon nanotubes, fullerenes and the various forms of diamond have attracted great attention for their vast potential regarding applications in electrical engineering and as biomaterials. The study of the antibacterial properties of carbon nanomaterials provides fundamental information on the possible toxicity and environmental impact of these materials. Furthermore, as a result of the increasing prevalence of resistant bacteria strains, the development of novel antibacterial materials is of great importance. This article reviews current research efforts on characterizing the antibacterial activity of carbon nanomaterials from the perspective of colloid and interface science. Building on these fundamental findings, recent functionalization strategies for enhancing the antibacterial effect of carbon nanomaterials are described. The review concludes with a comprehensive outlook that summarizes the most important discoveries and trends regarding antibacterial carbon nanomaterials.
Synthesis and Spectral Characterization of Benzo-[6,7][1,5]diazocino[2,1-a]isoindol-12-(14H)-one Derivatives
Authors: Bassin Jatinder , Anagani Bhavani , Benham Christopher , Goyal Madhu , Hashemian Maryam , Gerhard Ute
Published: July 2016

A simple synthetic route affording 27%–85% yields of benzo[6,7][1,5]diazocino[2,1-a]isoindol-12(14H)-one ring systems from readily available 3-(2-oxo-2-phenylethyl) isobenzofuran-1(3H)-ones and 2-(aminomethyl)aniline starting materials in toluene and catalysed by p-toluene-sulfonic acid is developed. The 1H- and 13C-NMR spectra of the final products were assigned using a variety of one and two-dimensional NMR experiments. The distinction between the two potential isomers of the final products was made on the basis of heteronuclear multiple bond connectivity (HMBC) NMR spectra.
Indole Alkaloids from the Leaves of Nauclea officinalis
Authors: Fan Long , Liao Cheng-Hui , Kang Qiang-Rong , Zheng Kai , Jiang Ying-Chun , He Zhen-Dan
Published: July 2016

Three new indole alkaloids, named naucleamide G (1), and nauclealomide B and C (5 and 6), were isolated from the n-BuOH-soluble fraction of an EtOH extract of the leaves of Nauclea officinalis, together with three known alkaloids, paratunamide C (2), paratunamide D (3) and paratunamide A (4). The structures with absolute configurations of the new compounds were identified on the basis of 1D and 2D NMR, HRESIMS, acid hydrolysis and quantum chemical circular dichroism (CD) calculation. According to the structures of isolated indole alkaloids, their plausible biosynthetic pathway was deduced.
Development of Chemical Process Design and Control for Sustainability
Authors: Li Shuyun , Mirlekar Gaurav , Ruiz-Mercado Gerardo , Lima Fernando
Published: July 2016

This contribution describes a novel process systems engineering framework that couples advanced control with sustainability evaluation for the optimization of process operations to minimize environmental impacts associated with products, materials and energy. The implemented control strategy combines a biologically-inspired method with optimal control concepts for finding more sustainable operating trajectories. The sustainability assessment of process operating points is carried out by using the U.S. EPA’s Gauging Reaction Effectiveness for the ENvironmental Sustainability of Chemistries with a multi-Objective Process Evaluator (GREENSCOPE) tool that provides scores for the selected indicators in the economic, material efficiency, environmental and energy areas. The indicator scores describe process performance on a sustainability measurement scale, effectively determining which operating point is more sustainable if there are more than several steady states for one specific product manufacturing. Through comparisons between a representative benchmark and the optimal steady states obtained through the implementation of the proposed controller, a systematic decision can be made in terms of whether the implementation of the controller is moving the process towards a more sustainable operation. The effectiveness of the proposed framework is illustrated through a case study of a continuous fermentation process for fuel production, whose material and energy time variation models are characterized by multiple steady states and oscillatory conditions.
An Analysis on Sensor Locations of the Human Body for Wearable Fall Detection Devices: Principles and Practice
Authors: Özdemir Ahmet
Published: July 2016

Wearable devices for fall detection have received attention in academia and industry, because falls are very dangerous, especially for elderly people, and if immediate aid is not provided, it may result in death. However, some predictive devices are not easily worn by elderly people. In this work, a huge dataset, including 2520 tests, is employed to determine the best sensor placement location on the body and to reduce the number of sensor nodes for device ergonomics. During the tests, the volunteer’s movements are recorded with six groups of sensors each with a triaxial (accelerometer, gyroscope and magnetometer) sensor, which is placed tightly on different parts of the body with special straps: head, chest, waist, right-wrist, right-thigh and right-ankle. The accuracy of individual sensor groups with their location is investigated with six machine learning techniques, namely the k-nearest neighbor (k-NN) classifier, Bayesian decision making (BDM), support vector machines (SVM), least squares method (LSM), dynamic time warping (DTW) and artificial neural networks (ANNs). Each technique is applied to single, double, triple, quadruple, quintuple and sextuple sensor configurations. These configurations create 63 different combinations, and for six machine learning techniques, a total of 63 × 6 = 378 combinations is investigated. As a result, the waist region is found to be the most suitable location for sensor placement on the body with 99.96% fall detection sensitivity by using the k-NN classifier, whereas the best sensitivity achieved by the wrist sensor is 97.37%, despite this location being highly preferred for today’s wearable applications.
Biotechnological Trends in Spider and Scorpion Antivenom Development
Authors: Laustsen Andreas , Solà Mireia , Jappe Emma , Oscoz Saioa , Lauridsen Line , Engmark Mikael
Published: July 2016

Spiders and scorpions are notorious for their fearful dispositions and their ability to inject venom into prey and predators, causing symptoms such as necrosis, paralysis, and excruciating pain. Information on venom composition and the toxins present in these species is growing due to an interest in using bioactive toxins from spiders and scorpions for drug discovery purposes and for solving crystal structures of membrane-embedded receptors. Additionally, the identification and isolation of a myriad of spider and scorpion toxins has allowed research within next generation antivenoms to progress at an increasingly faster pace. In this review, the current knowledge of spider and scorpion venoms is presented, followed by a discussion of all published biotechnological efforts within development of spider and scorpion antitoxins based on small molecules, antibodies and fragments thereof, and next generation immunization strategies. The increasing number of discovery and development efforts within this field may point towards an upcoming transition from serum-based antivenoms towards therapeutic solutions based on modern biotechnology.
Improved Transplanted Stem Cell Survival in a Polymer Gel Supplemented with Tenascin C Accelerates Healing and Reduces Scarring of Murine Skin Wounds
Authors: Yates Cecelia C. , Nuschke Austin , Rodrigues Melanie , Whaley Diana , Dechant Jason J. , Taylor Donald P. , Wells Alan
Published: July 2016

Mesenchymal stem cells (MSCs) remain of great interest in regenerative medicine because of their ability to home to sites of injury, differentiate into a variety of relevant lineages, and modulate inflammation and angiogenesis through paracrine activity. Many studies have found that despite the promise of MSC therapy, cell survival upon implant is highly limited and greatly reduces the therapeutic utility of MSCs. The matrikine tenascin C, a protein expressed often at the edges of a healing wound, contains unique EGF-like repeats that are able to bind EGFR at low affinities and induce downstream prosurvival signaling without inducing receptor internalization. In this study, we utilized tenascin C in a collagen/GAG-based polymer (TPolymer) that has been shown to be beneficial for skin wound healing, incorporating human MSCs into the polymer prior to application to mouse punch biopsy wound beds. We found that the TPolymer was able to promote MSC survival for 21 days in vivo, leading to associated improvements in wound healing such as dermal maturation and collagen content. This was most marked in a model of hypertrophic scarring, in which the scar formation was limited. This approach also reduced the inflammatory response in the wound bed, limiting CD3e+ cell invasion by approximately 50% in the early wound-healing process, while increasing the numbers of endothelial cells during the first week of wound healing as well. Ultimately, this matrikine-based approach to improving MSC survival may be of great use across a variety of cell therapies utilizing matrices as delivery vehicles for cells.
Stem Cell Delivery with Polymer Hydrogel for Treatment of Intervertebral Disc Degeneration: From 3D Culture to Design of the Delivery Device for Minimally Invasive Therapy
Authors: Kumar Deepak , Lyness Alex , Gerges Irini , Lenardi Christina , Forsyth Nicholas R. , Liu Yang
Published: July 2016

Nucleus pulposus (NP) tissue damage can induce detrimental mechanical strain on the biomechanical performance of intervertebral discs (IVDs), causing subsequent disc degeneration. A novel, photocurable, injectable, synthetic polymer hydrogel (pHEMA-co-APMA grafted with PAA) has already demonstrated success in encapsulating and differentiating human mesenchymal stem cells (hMSCs) toward an NP phenotype during hypoxic conditions. After demonstration of promising results in our previous work, in this study we have further investigated the inclusion of mechanical stimulation and its impact on hMSC differentiation toward an NP phenotype through the characterization of matrix markers such as SOX-9, aggrecan, and collagen II. Furthermore, investigations were undertaken in order to approximate delivery parameters for an injection delivery device, which could be used to transport hMSCs suspended in hydrogel into the IVD. hMSC-laden hydrogel solutions were injected through various needle gauge sizes in order to determine its impact on postinjection cell viability and IVD tissue penetration. Interpretation of these data informed the design of a potential minimally invasive injection device, which could successfully inject hMSCs encapsulated in a UV-curable polymer into NP, prior to photo-cross-linking in situ.
MAD ADAPTIVE OPTICS IMAGING OF HIGH-LUMINOSITY QUASARS: A PILOT PROJECT
Authors: Liuzzo E. , Falomo R. , Paiano S. , Treves A. , Uslenghi M. , Arcidiacono C. , Baruffolo A. , Diolaiti E. , Farinato J. , Lombini M. , Moretti A. , Ragazzoni R. , Brast R. , Donaldson R. , Kolb J. , Marchetti E. , Tordo S.
Published: July 2016

We present near-IR images of five luminous quasars at z ∼ 2 and one at z ∼ 4 obtained with an experimental adaptive optics (AO) instrument at the European Southern Observatory Very Large Telescope. The observations are part of a program aimed at demonstrating the capabilities of multi-conjugated adaptive optics imaging combined with the use of natural guide stars for high spatial resolution studies on large telescopes. The observations were mostly obtained under poor seeing conditions but in two cases. In spite of these nonoptimal conditions, the resulting images of point sources have cores of FWHM ∼ 0.2 arcsec. We are able to characterize the host galaxy properties for two sources and set stringent upper limits to the galaxy luminosity for the others. We also report on the expected capabilities for investigating the host galaxies of distant quasars with AO systems coupled with future Extremely Large Telescopes. Detailed simulations show that it will be possible to characterize compact (2–3 kpc) quasar host galaxies for quasi-stellar objects at z = 2 with nucleus K-magnitude spanning from 15 to 20 (corresponding to absolute magnitude −31 to −26) and host galaxies that are 4 mag fainter than their nuclei.
CAPTURE OF TRANS-NEPTUNIAN PLANETESIMALS IN THE MAIN ASTEROID BELT
Authors: Vokrouhlický David , Bottke William F. , Nesvorný David
Published: July 2016

The orbital evolution of the giant planets after nebular gas was eliminated from the Solar System but before the planets reached their final configuration was driven by interactions with a vast sea of leftover planetesimals. Several variants of planetary migration with this kind of system architecture have been proposed. Here, we focus on a highly successful case, which assumes that there were once five planets in the outer Solar System in a stable configuration: Jupiter, Saturn, Uranus, Neptune, and a Neptune-like body. Beyond these planets existed a primordial disk containing thousands of Pluto-sized bodies, ∼50 million D > 100 km bodies, and a multitude of smaller bodies. This system eventually went through a dynamical instability that scattered the planetesimals and allowed the planets to encounter one another. The extra Neptune-like body was ejected via a Jupiter encounter, but not before it helped to populate stable niches with disk planetesimals across the Solar System. Here, we investigate how interactions between the fifth giant planet, Jupiter, and disk planetesimals helped to capture disk planetesimals into both the asteroid belt and first-order mean-motion resonances with Jupiter. Using numerical simulations, we find that our model produces the right proportion of P- and D-type asteroids in the inner, central, and outer main belt, while also populating the Hilda and Thule regions in Jupiter’s 3/2 and 4/3 resonances. Moreover, the largest observed P/D types in each sub-population are an excellent fit to our captured population results (within uncertainties). The model produces a factor of ∼10 overabundance of diameter D > 10 km P/D types in the main belt, but this mismatch can likely be explained by various removal mechanisms (e.g., collision evolution over 4 Gyr, dynamical losses via Yarkovsky thermal forces over 4 Gyr, thermal destruction of the planetesimals en route to the inner solar system). Overall, our instability model provides a more satisfying match to constraints than that of Levison et al., and it provides us with strong supporting evidence that the five giant planet instability model is reasonable. Our results lead us to predict that D-type asteroids found in the near-Earth object population on low delta-V orbits with Earth are the surviving relics from the same source population that now make up the Kuiper Belt, the irregular satellites, and the Jupiter Trojans. The singular Tagish Lake meteorite, a primitive sample unlike other carbonaceous chondrite meteorites, is likely a fragment from a D-type asteroid implanted into the inner main belt. This would effectively make it the first known hand sample with the same composition as Kuiper Belt objects.
THE CLOSE COMPANION MASS-RATIO DISTRIBUTION OF INTERMEDIATE-MASS STARS
Authors: Gullikson Kevin , Kraus Adam , Dodson-Robinson Sarah
Published: July 2016

Binary stars and higher-order multiple systems are a ubiquitous outcome of star formation, especially as the system mass increases. The companion mass-ratio distribution is a unique probe into the conditions of the collapsing cloud core and circumstellar disk(s) of the binary fragments. Inside

the disks from the two forming stars can interact, and additionally companions can form directly through disk fragmentation. We should, therefore, expect the mass-ratio distribution of close companions (

AU) to differ from that of wide companions. This prediction is difficult to test using traditional methods, in particular, with intermediate-mass primary stars, for a variety of observational reasons. We present the results of a survey searching for companions to A- and B-type stars using the direct spectral detection method, which is sensitive to late-type companions within

of the primary and which has no inner working angle. We estimate the temperatures and surface gravity of most of the 341 sample stars and derive their masses and ages. We additionally estimate the temperatures and masses of the 64 companions we find, 23 of which are new detections. We find that the mass-ratio distribution for our sample has a maximum near

. Our mass-ratio distribution has a very different form than in previous works, where it is usually well-described by a power law, and indicates that close companions to intermediate-mass stars experience significantly different accretion histories or formation mechanisms than wide companions.
EFFECT OF A SAUSAGE OSCILLATION ON RADIO ZEBRA-PATTERN STRUCTURES IN A SOLAR FLARE
Authors: Yu Sijie , Nakariakov V. M. , Yan Yihua
Published: July 2016

Sausage modes that are axisymmetric fast magnetoacoustic oscillations of solar coronal loops are characterized by variation of the plasma density and magnetic field, and hence cause time variations of the electron plasma frequency and cyclotron frequency. The latter parameters determine the condition for the double plasma resonance (DPR), which is responsible for the appearance of zebra-pattern (ZP) structures in time spectra of solar type IV radio bursts. We perform numerical simulations of standing and propagating sausage oscillations in a coronal loop modeled as a straight, field-aligned plasma slab, and determine the time variation of the DPR layer locations. Instant values of the plasma density and magnetic field at the DPR layers allowed us to construct skeletons of the time variation of ZP stripes in radio spectra. In the presence of a sausage oscillation, the ZP structures are shown to have characteristic wiggles with the time period prescribed by the sausage oscillation. Standing and propagating sausage oscillations are found to have different signatures in ZP patterns. We conclude that ZP wiggles can be used for the detection of short-period sausage oscillations and the exploitation of their seismological potential.
INVESTIGATING THE CIRCUMSTELLAR DISK OF THE Be SHELL STAR 48 LIBRAE
Authors: Silaj J. , Jones C. E. , Carciofi A. C. , Escolano C. , Okazaki A. T. , Tycner C. , Rivinius T. , Klement R. , Bednarski D.
Published: July 2016

A global disk oscillation implemented in the viscous decretion disk (VDD) model has been used to reproduce most of the observed properties of the well known Be star ζ Tau. 48 Librae shares several similarities with ζ Tau—they are both early-type Be stars, display shell characteristics in their spectra, and exhibit cyclic V/R variations—but has some marked differences as well, such as a much denser and more extended disk, a much longer V/R cycle, and the absence of the so-called triple-peak features. We aim to reproduce the photometric, polarimetric, and spectroscopic observables of 48 Librae with a self-consistent model, and to test the global oscillation scenario for this target. Our calculations are carried out with the three-dimensional NLTE radiative transfer code HDUST. We employ a rotationally deformed, gravity-darkened central star surrounded by a disk whose unperturbed state is given by the VDD model. A two-dimensional global oscillation code is then used to calculate the disk perturbation and superimpose it on the unperturbed disk. A very good, self-consistent fit to the time-averaged properties of the disk is obtained with the VDD. The calculated perturbation has a period P = 12 years, which agrees with the observed period, and the behavior of the V/R cycle is well reproduced by the perturbed model. The perturbed model improves the fit to the photometric data and reproduces some features of the observed spectroscopic data. Some suggestions to improve the synthesized spectroscopy in a future work are given.
ACCELERATED FITTING OF STELLAR SPECTRA
Authors: Ting (丁源森) Yuan-Sen , Conroy Charlie , Rix Hans-Walter
Published: July 2016

Stellar spectra are often modeled and fitted by interpolating within a rectilinear grid of synthetic spectra to derive the stars’ labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of labels separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach—Convex Hull Adaptive Tessellation (chat)—which includes several new ideas for inexpensively generating a sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock data sets demonstrate that chat can reduce the number of required synthetic model calculations by three orders of magnitude in an eight-dimensional label space. The reduction will be even larger for higher dimensional label spaces. In chat the computational effort increases only linearly with the number of labels that are fit simultaneously. Around each of these grid points in the label space an approximate synthetic spectrum can be generated through linear expansion using a set of “gradient spectra” that represent flux derivatives at every wavelength point with respect to all labels. These techniques provide new opportunities to fit the full stellar spectra from large surveys with 15–30 labels simultaneously.
THE BINARY NATURE OF CH-LIKE STARS
Authors: Sperauskas J. , Začs L. , Schuster W. J. , Deveikis V.
Published: July 2016

Yamashita has described a group of early carbon stars with enhanced lines of barium that resemble the CH stars but have low radial velocities. It is not clear whether they represent a class of stars separate from early R stars. Radial-velocity measurements and abundance analyses are applied in order to clarify the evolutionary status of CH-like stars. Radial-velocity monitoring was performed over a time interval of about 10 years. Abundance analysis was carried out using high-resolution spectra and the method of atmospheric models for three CH-like candidate stars. The radial-velocity monitoring confirmed regular variations for all of the classified CH-like stars, except for two, in support of their binary nature. The calculated orbital parameters are similar to those observed for barium stars in the disk of the Galaxy and their counterparts in the halo, that is, the CH stars. The relatively low luminosity of CH-like stars and the overabundance of s-process elements in the atmospheres are in agreement with a mass-transfer scenario from the secondary—an AGB star in the past. The kinematic data and metallicities support the idea that CH-like stars are thin/thick-disk population objects.
PSR J1024–0719: A MILLISECOND PULSAR IN AN UNUSUAL LONG-PERIOD ORBIT
Authors: Kaplan David L. , Kupfer Thomas , Nice David J. , Irrgang Andreas , Heber Ulrich , Arzoumanian Zaven , Beklen Elif , Crowter Kathryn , DeCesar Megan E. , Demorest Paul B. , Dolch Timothy , Ellis Justin A. , Ferdman Robert D. , Ferrara Elizabeth C. , Fonseca Emmanuel , Gentile Peter A. , Jones Glenn , Jones Megan L. , Kreuzer Simon , Lam Michael T. , Levin Lina , Lorimer Duncan R. , Lynch Ryan S. , McLaughlin Maura A. , Miller Adam A. , Ng Cherry , Pennucci Timothy T. , Prince Tom A. , Ransom Scott M. , Ray Paul S. , Spiewak Renee , Stairs Ingrid H. , Stovall Kevin , Swiggum Joseph , Zhu Weiwei
Published: July 2016

PSR J1024–0719 is a millisecond pulsar that was long thought to be isolated. However, puzzling results concerning its velocity, distance, and low rotational period derivative have led to a reexamination of its properties. We present updated radio timing observations along with new and archival optical data which show that PSR J1024–0719 is most likely in a long-period (2–20 kyr) binary system with a low-mass (

), low-metallicity (

dex) main-sequence star. Such a system can explain most of the anomalous properties of this pulsar. We suggest that this system formed through a dynamical exchange in a globular cluster that ejected it into a halo orbit, which is consistent with the low observed metallicity for the stellar companion. Further astrometric and radio timing observations such as measurement of the third period derivative could strongly constrain the range of orbital parameters.
A POSSIBLE SOLUTION FOR THE M/L–[Fe/H] RELATION OF GLOBULAR CLUSTERS IN M31. I. A METALLICITY- AND DENSITY-DEPENDENT TOP-HEAVY IMF
Authors: Zonoozi A. H. , Haghi H. , Kroupa P.
Published: July 2016

The observed mass-to-light (M/L) ratios of a large sample of globular clusters (GCs) in M31 show an inverse trend with metallicity compared to what is expected from simple stellar population (SSP) models with an invariant canonical stellar initial mass function (IMF), in the sense that the observed M/L ratios decrease with increasing metallicity. We show that when incorporating the effect of dynamical evolution the SSP models with a canonical IMF cannot explain the decreasing M/L ratios with increasing metallicity for the M31 GCs. The recently derived top-heavy IMF as a function of metallicity and embedded cluster density is proposed to explain the lower-than-expected M/L ratios of metal-rich GCs. We find that the SSP models with a top-heavy IMF, retaining a metallicity- and cluster-mass-dependent fraction of the remnants within the clusters, and taking standard dynamical evolution into account, can successfully explain the observed M/L–[Fe/H] relation of M31 GCs. Thus we propose that the kinematic data of GCs can be used to constrain the top-heaviness of the IMF in GCs.
A GROWTH-RATE INDICATOR FOR COMPTON-THICK ACTIVE GALACTIC NUCLEI
Authors: Brightman M. , Masini A. , Ballantyne D. R. , Baloković M. , Brandt W. N. , Chen C.-T. , Comastri A. , Farrah D. , Gandhi P. , Harrison F. A. , Ricci C. , Stern D. , Walton D. J.
Published: July 2016

Due to their heavily obscured central engines, the growth rate of Compton-thick (CT) active galactic nuclei (AGNs) is difficult to measure. A statistically significant correlation between the Eddington ratio, λ
Edd, and the X-ray power-law index, Γ, observed in unobscured AGNs offers an estimate of their growth rate from X-ray spectroscopy (albeit with large scatter). However, since X-rays undergo reprocessing by Compton scattering and photoelectric absorption when the line of sight to the central engine is heavily obscured, the recovery of the intrinsic Γ is challenging. Here we study a sample of local, predominantly CT megamaser AGNs, where the black hole mass, and thus Eddington luminosity, are well known. We compile results of the X-ray spectral fitting of these sources with sensitive high-energy (E > 10 keV) NuSTAR data, where X-ray torus models, which take into account the reprocessing effects have been used to recover the intrinsic Γ values and X-ray luminosities, L
X. With a simple bolometric correction to L
X to calculate λ
Edd, we find a statistically significant correlation between Γ and λ
Edd (p = 0.007). A linear fit to the data yields Γ = (0.41 ± 0.18)log10
λ
Edd + (2.38 ± 0.20), which is statistically consistent with results for unobscured AGNs. This result implies that torus modeling successfully recovers the intrinsic AGN parameters. Since the megamasers have low-mass black holes (M
BH ≈ 106–107
M
⊙) and are highly inclined, our results extend the Γ–λ
Edd relationship to lower masses and argue against strong orientation effects in the corona, in support of AGN unification. Finally this result supports the use of Γ as a growth-rate indicator for accreting black holes, even for CT AGNs.
EXPLORING THE POTENTIAL DIVERSITY OF EARLY TYPE IA SUPERNOVA LIGHT CURVES
Authors: Piro Anthony L. , Morozova Viktoriya S.
Published: July 2016

During the first several days after explosion, Type Ia supernova light curves probe the outer layers of the exploding star, and therefore provide important clues for identifying their progenitors. We investigate how both the shallow 56Ni distribution and the presence of circumstellar material shape these early light curves. This is performed using a series of numerical experiments with parameterized properties for systematic exploration. Although not all of the considered models may be realized in nature (and indeed there are arguments why some of them should not occur), the spirit of this work is to provide a broader exploration of the diversity of possibilities. We find that shallower 56Ni leads to steeper, bluer light curves. Differences in the shape of the rise can introduce errors in estimating the explosion time, and thus impact efforts to infer upper limits on the progenitor or companion radius from a lack of observed shock cooling emission. Circumstellar material can lead to significant luminosity during the first few days, but its presence can be difficult to identify depending on the degree of nickel mixing. In some cases, the hot emission of circumstellar material may even lead to a signature similar to an interaction with a companion, and thus in the future additional diagnostics should be gathered for properly assessing early light curves.
ULTRAHIGH-ENERGY COSMIC RAYS FROM THE “EN CAUL” BIRTH OF MAGNETARS*
Authors: Piro Anthony L. , Kollmeier Juna A.
Published: July 2016

Rapidly spinning magnetars can potentially form through the accretion induced collapse of a white dwarf or by neutron star (NS) mergers if the equation of state of the nuclear density matter is such that two low-mass NSs can form a massive NS rather than a black hole. In either case, the newborn magnetar is an attractive site for the production of ultrahigh-energy cosmic rays (particles with individual energies exceeding

UHECRs). The short-period spin and strong magnetic field are able to accelerate particles up to appropriate energies, and the composition of material on and around the magnetar may naturally explain recent inferences of heavy elements in UHECRs. We explore whether the small amount of natal debris surrounding these magnetars allows UHECRs to escape easily. We also investigate the impact on the UHECRs of the unique environment around the magnetar, which consists of a bubble of relativistic particles and magnetic field within the debris. The rates and energetics of UHECRs are consistent with such an origin, even though the rates of events that produce rapidly spinning magnetars remain very uncertain. The low ejecta mass also helps the high-energy neutrino background associated with this scenario to be below current IceCube constraints over most of the magnetar parameter space. A unique prediction is that UHECRs may be generated in old stellar environments without strong star formation, in contrast to what would be expected for other UHECR scenarios, such as active galactic nuclei or long gamma-ray bursts.
INVESTIGATION OF PRIMORDIAL BLACK HOLE BURSTS USING INTERPLANETARY NETWORK GAMMA-RAY BURSTS
Authors: Ukwatta T. N. , Hurley K. , MacGibbon J. H. , Svinkin D. S. , Aptekar R. L. , Golenetskii S. V. , Frederiks D. D. , Pal'shin V. D. , Goldsten J. , Boynton W. , Kozyrev A. S. , Rau A. , Kienlin A. von , Zhang X. , Connaughton V. , Yamaoka K. , Ohno M. , Ohmori N. , Feroci M. , Frontera F. , Guidorzi C. , Cline T. , Gehrels N. , Krimm H. A. , McTiernan J.
Published: July 2016

The detection of a gamma-ray burst (GRB) in the solar neighborhood would have very important implications for GRB phenomenology. The leading theories for cosmological GRBs would not be able to explain such events. The final bursts of evaporating primordial black holes (PBHs), however, would be a natural explanation for local GRBs. We present a novel technique that can constrain the distance to GRBs using detections from widely separated, non-imaging spacecraft. This method can determine the actual distance to the burst if it is local. We applied this method to constrain distances to a sample of 36 short-duration GRBs detected by the Interplanetary Network (IPN) that show observational properties that are expected from PBH evaporations. These bursts have minimum possible distances in the 1013–1018 cm (7–105 au) range, which are consistent with the expected PBH energetics and with a possible origin in the solar neighborhood, although none of the bursts can be unambiguously demonstrated to be local. Assuming that these bursts are real PBH events, we estimate lower limits on the PBH burst evaporation rate in the solar neighborhood.
A SPECTROSCOPICALLY CONFIRMED DOUBLE SOURCE PLANE LENS SYSTEM IN THE HYPER SUPRIME-CAM SUBARU STRATEGIC PROGRAM
Authors: Tanaka Masayuki , Wong Kenneth C. , More Anupreeta , Dezuka Arsha , Egami Eiichi , Oguri Masamune , Suyu Sherry H. , Sonnenfeld Alessandro , Higuchi Ryo , Komiyama Yutaka , Miyazaki Satoshi , Onoue Masafusa , Oyamada Shuri , Utsumi Yousuke
Published: July 2016

We report the serendipitous discovery of HSC J142449−005322, a double source plane lens system in the Hyper Suprime-Cam Subaru Strategic Program. We dub the system Eye of Horus. The lens galaxy is a very massive early-type galaxy with stellar mass of

∼
7
×

10

11

M

⊙

located at

z

L

=
0.795

. The system exhibits two arcs/rings with clearly different colors, including several knots. We have performed spectroscopic follow-up observations of the system with FIRE on Magellan. The outer ring is confirmed at

z

S
2

=
1.988

with multiple emission lines, while the inner arc and counterimage is confirmed at

z

S
1

=
1.302

. This makes it the first double source plane system with spectroscopic redshifts of both sources. Interestingly, redshifts of two of the knots embedded in the outer ring are found to be offset by

Δ
z
=
0.002

from the other knots, suggesting that the outer ring consists of at least two distinct components in the source plane. We perform lens modeling with two independent codes and successfully reproduce the main features of the system. However, two of the lensed sources separated by ∼0.7 arcsec cannot be reproduced by a smooth potential, and the addition of substructure to the lens potential is required to reproduce them. Higher-resolution imaging of the system will help decipher the origin of this lensing feature and potentially detect the substructure.
PLASMA SLOSHING IN PULSE-HEATED SOLAR AND STELLAR CORONAL LOOPS
Authors: Reale F.
Published: July 2016

There is evidence that coronal heating is highly intermittent, and flares are the high energy extreme. The properties of the heat pulses are difficult to constrain. Here, hydrodynamic loop modeling shows that several large amplitude oscillations (∼20% in density) are triggered in flare light curves if the duration of the heat pulse is shorter than the sound crossing time of the flaring loop. The reason for this is that the plasma does not have enough time to reach pressure equilibrium during heating, and traveling pressure fronts develop. The period is a few minutes for typical solar coronal loops, dictated by the sound crossing time in the decay phase. The long period and large amplitude make these oscillations different from typical magnetohydrodynamic (MHD) waves. This diagnostic can be applied both to observations of solar and stellar flares and to future observations of non-flaring loops at high resolution.
Fenêtres sur la littérature yéménite contemporaine
Authors: Haytham Muhammad Husayn , Ayoub Houda , Boisson Hélène , al-Surayhi Abdurahman , Monassar Samir , Dufour Julien , Lévêque Mathilde , Bâ Wazîr
Published: July 2016

Cinq poèmes et trois nouvelles d'auteurs yéménites contemporains sont ici traduits en français. De la première génération (Muhammad al-Sharafî) à la génération montante (Wajdî al-Ahdal), de la satire à l'écriture féminine, se mêlent les thèmes et les formes de cette " jeune " littérature.
Vers une archéologie préventive au Yémen
Authors: Arbach Mounir , Crassard Rémy , Hitgen Holger , Khalidi Lamya
Published: July 2016

L’archéologie préventive et les opérations de sauvetage archéologique et de protection du patrimoine se sont amplifiées au cours des dernières décennies au Yémen. Les autorités locales ont rapidement pris conscience du danger que pouvait représenter les aménagements modernes du territoire sur la préservation des connaissances scientifiques du passé. De même, les pillages opérés à l’encontre de la loi en vigueur sur la protection des antiquités se sont développés parallèlement à l’intérêt croissant des marchands d’art. Le présent article tente de situer la place des actions scientifiques d’urgence au sein de la recherche archéologique plus traditionnelle, en comparaison avec la situation observée en France. Le cadre de la loi yéménite est également analysé afin de déterminer sa valeur et son application. Des opérations récentes sont ensuite présentées, dans la perspective du développement plus organisé des recherches archéologiques préventives au Yémen.
Manuscrits de provenance yéménite donnés à la Bibliothèque nationale par Pierre Bardey en 1930
Authors: Guesdon Marie-Geneviève
Published: July 2016

Pierre Bardey, l’un des principaux donateurs d’objets sudarabiques au Musée du Louvre a également donné en 1930 à la Bibliothèque nationale dix‑sept manuscrits qu’il avait acquis lors de son long séjour au Yémen. Onze de ceux‑ci sont datés, du XIVe au XIXe s. La plupart ont été copiés au Yémen. Leur observation montre la persistance à travers les siècles de caractéristiques propres au Yémen, notamment dans la graphie de certaines lettres arabes, accompagnée d’une évolution commune à l’ensemble du Moyen Orient  pour la fabrication des manuscrits.
Monothéisme en Arabie du Sud préislamique
Authors: Gajda Iwona
Published: July 2016

A la fin du IVe siècle de l'ère chrétienne, l'Arabie du Sud abandonne les cultes polythéistes et adopte le monothéisme. Dès lors, les inscriptions monothéistes se multiplient. Un certain nombre d'entre elles sont juives ou judaïsantes alors qu'aucune inscription royale n'est explicitement juive. Cet article présente une courte synthèse de nos connaissances sur le monothéisme en Arabie du Sud avant l'islam. L'accent est mis sur la dimension politique et non uniquement religieuse des conflits du VIe siècle qui opposèrent le roi juif Yûsuf aux Ethiopiens chrétiens essayant de conquérir l'Arabie du Sud et leurs alliées, les chrétiens /himyarites. Le caractère de la religion officielle avant les conflits du VIe siècle est discuté en fin de l'article. L'auteur suggère d'y voir un monothéisme judaïsant plutôt que le judaïsme.
Aux origines de la langue poétique sanaanie
Authors: Dufour Julien
Published: July 2016

Mu/hammad b. Sharaf al-Dîn est, autant qu'on le sache, le premier poète des régions zaydites à avoir composé dans le genre /humaynî. L'examen de la langue de cette poésie non classique montre la première étape d'un processus qui a vu s'acclimater dans les Hauts plateaux une langue poétique élaborée d'abord dans les basses terres à l'époque rasoulide. Ne s'astreignant pas aux canons de l'arabe littéral tout en y puisant largement, évitant les particularités dialectales trop marquées à l'exception de quelques-unes qu'elle adopte dans sa norme, la langue de ce poète sera à la base de celle d'un des principaux genres poético-musicaux du Yémen contemporain : le chant de Sanaa.