bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of branched benzoxazine monomers with high molecular mass, wide processing window, and properties of corresponding polybenzoxazines
Authors: Ma Hong‐Xia , Zhao Chen , Qiu Jin‐Jun , Liu Yun , Liu Cheng‐Mei 
Published: September 2016

ABSTRACTFour cyclotriphosphazene‐based benzoxazine monomers (I, II, III, and IV) with relatively high molecular weight were synthesized by a nucleophilic substitution reaction, and their chemical structures were confirmed by1H‐NMR and31P‐NMR. A new term, oxazine value (OV, similar to epoxy value), was first proposed to explain the structure–property relationship of the cured polymers. The polymerization behaviors of the four monomers were studied by differential scanning calorimetry and Fourier transform infrared spectroscopy. The maximum exothermic peaks of the four monomers are in the range 244–248 °C. All monomers possess a wide processing window despite their high molecular weight. The thermal stability, glass‐transition temperature (Tg), and mechanical properties of each cured polymer were studied by thermogravimetric analysis and dynamic mechanical thermal analysis. The char yield at 850 °C,Tg, and storage moduli of PIV (polybenzoxazine obtained from monomer IV) are 60.0%, 218 °C, and 9.0 GPa, respectively. The surface property and humidity absorption character of the cured polybenzoxazines were also studied. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2017,134, 44453.
Dynamically controlled fibrillation under combination of ionic liquid with mechanical grinding
Authors: Eksiler Kubra , Andou Yoshito , Yilmaz Faruk , Shirai Yoshihito , Ariffin Hidayah , Hassan Mohd Ali 
Published: September 2016

ABSTRACTCombination of mortar grinder mill (MG) and ionic liquid (IL) treatment was employed in order to fibrillate fibers from oil palm mesocarp fiber (OPMF) in one‐step. The structural changes of OPMF before and after the treatment were examined by Thermogravimetric analysis (TGA), Fourier transformed infrared (FT‐IR) spectra, Wide‐angle X‐ray diffraction (WAXD), Dynamic light scattering (DLS) and Scanning electron microscopy (SEM). Compared with the only use of 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIM[BF4]), combination of MG and IL helped to remove hemicellulose and lignin components partially from OPMF, and also fibrillated OPMF fibers at average particle diameter of 127 nm. Afterwards, the fibrillated fibers were utilized as reinforcement material for the purpose of enhancement of mechanical properties of poly(ɛ‐caprolactone)(PCL). The addition of OPMF treated with the combined method led to a 64% increase in tensile strength in comparison with that of untreated OPMF. These results indicate that the combined method enables effective fibrillation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2017,134, 44469.
Chitosan/OA nanoparticle as delivery system for celecoxib: Parameters affecting the particle size, encapsulation, and release
Authors: Méndez Paula A. , Vásquez Gloria M. , Gartner Carmiña , López Betty L. 
Published: September 2016

ABSTRACTSelf‐assembled nanoparticles prepared from amphiphilic chitosan/oleic acid (Ch/OA) have shown antibacterial activity and potential application as a carrier for hydrophobic anticancer drugs. In this study, a low molecular weight chitosan was modified with oleic acid obtaining a degree of substitution (DS) of 12%. The critical aggregation concentration (CAC) of the Ch/OA polymer obtained (0.025 mg mL−1) is lower in comparison with some systems of chitosan‐fatty acids. The self‐assembled Ch/OA nanoparticle size was optimized by changing polymer concentration, solvent, method, and time of homogenization to obtain particles with sizes around 300 nm and positive zeta potential. The drug loading about 7 μg mL−1 and encapsulation efficiency of 75.8 ± 3.6% for Celecoxib was affected by the drug concentration. In vitro release behavior performed in (PBS, pH 7.4) and MES buffer (pH 6) indicated a pH‐dependent drug release behavior. The self‐assembled systems show stability during 4 weeks after the encapsulation of the hydrophobic drug. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44472.
The effect of injection molding process parameters on mechanical and fracture behavior of polycarbonate polymer
Authors: Dar Uzair Ahmed , Xu Ying Jie , Zakir Sheikh Muhammad , Saeed Muhammad‐Umar 
Published: September 2016

ABSTRACTIn this work, the mechanical and failure behavior of injection molded aviation standard optical grade polycarbonate (PC) was investigated through uniaxial tensile testing. The effect of different injection molding process parameters including injection velocity, packing pressure, cooling time, mold temperature, and melt temperature were determined to observe their effect on yield and postyield behavior of PC. Out of these examined parameters, the mold and melt temperature show significant effect on mechanical behavior of studied polymer. The yield and flow stresses in polymer increase with the increase in mold and melt temperature during injection molding. However, other process parameters i.e., packing pressure, injection velocity, and cooling time showed little effect on mechanical performance of the polymer. The molded specimens were annealed at different temperatures and residence time to evaluate its effect on mechanical behavior and fracture morphology. The yield stress increases gradually with the increase in annealing temperature and time. The annealing treatment also changed the failure mode of PC specimens from ductile to brittle. In addition to process parameters, the effect of increased loading rate was also undertaken which shows substantial effect on mechanical and failure behavior of PC. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44474.
Detection of Buried Roman Wall Remains in Ground‐penetrating Radar Data using Template Matching
Authors: Verdonck Lieven 
Published: September 2016

AbstractWhereas in the last decades the acquisition and processing of archaeological ground‐penetrating radar (GPR) data have become mature, the interpretation is still challenging. Manual delineation in three dimensions is time consuming, and often the determination of an isosurface value is not straightforward. This paper presents a method designed specifically for the extraction of buried linear features such as wall foundations, based on template matching. First, the three‐dimensional (3D) GPR data cube is synthesized into a two‐dimensional (2D) slice. To achieve this, an energy slice based on a sufficiently large time window may often be appropriate, although in this study a combination with other attributes, for example based on phase symmetry, made weak anomalies more distinct. In the next step, we compute the 2D normalized cross‐correlation of the composite 2D slice and a number of templates with dimensions similar to the walls in the data set. Of the resulting correlation matrices, the highest correlation coefficient is kept for each pixel, if it exceeds a certain threshold. In this way, wall foundations are successfully mapped, but also many false detections are produced. The latter are greatly reduced in number by using a size threshold and discarding isolated features. The remaining regions are enclosed in bounding boxes, which after vertical extrusion can be used as a simplified 3D representation of the wall structures, and for the creation of a filtered isosurface. For the evaluation of our results, a manual interpretation was used. In the 2D case (i.e. when comparing the total area of the automatically mapped structures versus the manually delineated ones), both the detection rate and the correctness were ~77%. Slightly lower rates (~71%) were obtained in the 3D case (i.e. comparing volumes). Our method was applied to the GPR survey of a Roman villa in Kent, UK. Copyright © 2016 John Wiley & Sons, Ltd.
Joined Interpretation of Buried Anomalies from Ground Penetrating Radar Data and Endoscopic Tests
Authors: Matera Loredana , Persico Raffaele , Bianco Nadia , Leopizzi Gaetano , Leopizzi Giuseppe 
Published: September 2016

AbstractThis paper presents ground penetrating radar (GPR) results joined with and back‐upped by endoscopic tests performed in two churches. The aim of this work is to show how the endoscopic tests can help the interpretation of the achieved GPR images, and this will be shown with respect to two case histories in southern Italy. The usefulness of the endoscopic tests depends on the kind of targets, but is expected to be particularly useful in cases of buried cavities, where information about the volume and the possible past use of the cavity can be retrieved. In the examined cases, the endoscopic tests allowed the presence of three cavities to be established, helping also in the interpretation of their possible nature and use, even if the endoscopic probe was not gyroscopic nor equipped with a laser for the precise measure of the distances. Copyright © 2016 John Wiley & Sons, Ltd.
Archaeological Applications of Low‐Cost Integrated Sidescan Sonar/Single‐Beam Echosounder Systems in Irish Inland Waterways
Authors: Westley Kieran , Mcneary Rory 
Published: September 2016

AbstractInland waterways, such as rivers and lakes have been foci of human settlement and use for millennia. However, underwater archaeological prospection or survey in these environments is often hindered by poor or no‐visibility conditions. While this can be overcome using a range of well‐established geophysical techniques, their application in inland waterways seems comparatively less common than in offshore environments. Possible reasons include the logistical challenges of surveying shallow confined, often inaccessible and uncharted waters coupled with a wider lack of awareness of the submerged archaeological potential of inland waterways. This paper demonstrates one method by which the logistical challenge can be circumvented, specifically the use of low‐cost acoustic systems which combine a single‐beam echo sounder and sidescan sonar. These systems have appeared within the last decade and are smaller and cheaper than their survey‐grade counterparts. Although developed for the sport fishing community, as shown here, they can also be used for archaeological purposes. Their effectiveness for archaeological prospection is illustrated via three case studies from lacustrine and riverine settings in Northern Ireland and by reference to object detection and bathymetric mapping. The data presented indicate that the low‐cost systems are capable of collecting data that is sufficient for archaeological purposes but they are best suited to shallow confined waters where their disadvantages (limited range and depth of operation, reduced image quality) are minimized. Copyright © 2016 John Wiley & Sons, Ltd.
Testing asteroseismic scaling relations using eclipsing binaries in star clusters and the field
Authors: Brogaard K. , Jessen‐Hansen J. , Handberg R. , Arentoft T. , Frandsen S. , Grundahl F. , Bruntt H. , Sandquist E. L. , Miglio A. , Beck P. G. , Thygesen A. O. , Kjærgaard K. L. , Haugaard N. A. 
Published: September 2016

AbstractThe accuracy of stellar masses and radii determined from asteroseismology is not known! We examine this issue for giant stars by comparing classical measurements of detached eclipsing binary systems (dEBs) with asteroseismic measurements from the Kepler mission. For star clusters, we extrapolate measurements of dEBs in the turn‐off region to the red giant branch and the red clump where we investigate the giants as an ensemble. For the field stars, we measure dEBs with an oscillating giant component. These measurements allow a comparison of masses and radii calculated from a classical eclipsing binary analysis to those calculated from asteroseismic scaling relations and/or other asteroseismic methods. Our first results indicate small but significant systematic differences between the classical and asteroseismic measurements. In this contribution we show our latest results and summarize the current status and future plans. We also stress the importance of realizing that for giant stars mass cannot always be translated to age, since an unknown fraction of these evolved through a blue straggler phase with mass transfer in a binary system. Rough estimates of how many such stars to expect are given based on our findings in the open clusters NGC 6819 and NGC 6791.
Models of rotating stars constrained by asteroseismic measurements of red giants
Authors: Eggenberger P. , Lagarde N. , Miglio A. , Montalbán J. , Ekström S. , Georgy C. , Salmon S. , Meynet G. , Maeder A. 
Published: September 2016

AbstractSolar‐like oscillations have now been characterized for a large number of stars, thanks to asteroseismic data obtained recently by space missions. This has led to the determination of the global and internal properties of these stars. In particular, core rotation rates have been obtained for red‐giant stars, which is of prime importance for progress in the modelling of the dynamical processes at work in stellar interiors. In this presentation, we discuss which constraints can be brought by these asteroseismic measurements on stellar models that include rotational effects. Similarly to the solar case, we show that an efficient mechanism is required for the transport of angular momentum in the radiative zones of red giants. The efficiency of this transport process can be determined by asteroseismic observations of red‐giant stars.
Dynamical and chemical evolution of the thin disc
Authors: Just A. , Rybizki J. 
Published: September 2016

AbstractOur detailed analytic local disc model (JJ‐model) quantifies the interrelation between kinematic properties (e.g. velocity dispersions and asymmetric drift), spatial parameters (scale‐lengths and vertical density profiles), and properties of stellar sub‐populations (age and abundance distributions). Any consistent radial extension of the disc evolution model should predict specific features in the different distribution functions and in their correlations. Large spectroscopic surveys (SEGUE, RAVE, APOGEE, Gaia‐ESO) allow significant constraints on the long‐term evolution of the thin disc. We discuss the qualitative difference of correlations (like the α‐enhancement as function of metallicity) and distribution functions (e.g. in [Mg/H] or [Fe/H]) for the construction of a disc model. In the framework of the JJ‐model we build a local chemical enrichment model and show that significant vertical gradients for main sequence and red clump stars are expected in the thin disc. A Jeans analysis of the asymmetric drift provides a link to the radial structure of the disc. The derived metallicitydependent radial scale‐lengths can be combined in the future with the abundance distributions at different Galactocentric distances to construct full disc models. We expect to be able to constrain possible scenarios of inside‐out growth of the thin disc and to characterise those populations, which require significant radial migration.
Radial migration in numerical simulations of Milky‐Way sized galaxies
Authors: Grand R. J. J. , Kawata D. 
Published: September 2016

AbstractWe show that in rmN ‐body simulations of isolated spiral discs, spiral arms appear to transient, recurring features that co‐rotate with the stellar disc stars at all radii. As a consequence, stars around the spiral arm continually feel a tangential force from the spiral and gain/lose angular momentum at all radii where spiral structure exists, without gaining significant amounts of random energy. We demonstrate that the ubiquitous radial migration in these simulations can be seen as outward (inward) systematic streaming motions along the trailing (leading) side of the spiral arms. We characterise these spiral induced peculiar motions and compare with those of the Milky Way obtained from APOGEE red clump data. We find that transient, co‐rotating spiral arms are consistent with the data, in contrast with density wave‐like spirals which are qualitatively inconsistent. In addition, we show that, in our simulations, radial migration does not change the radial metallicity gradient significantly, and broadens the metallicity distribution function at all radii, similar to some previous studies.
Peakbagging in the open cluster NGC 6819: Opening a treasure chest or Pandora's box?
Authors: Handberg R. , Miglio A. , Brogaard K. , Bossini D. , Elsworth Y. P. 
Published: September 2016

AbstractHere we report on an extensive peakbagging effort on the evolved red giant stars of the open cluster NGC 6819. This consists of around 50 stars spanning all the way up the red giant branch (RGB) and down to and including the red clump (RC). These stars represent a unique sample because of their common distance, metallicity and age. By employing sophisticated pre‐processing of the time series and Markov Chain Monte Carlo (MCMC) techniques, we have extracted individual frequencies, heights, and line widths for hundreds of individual oscillation modes in the sample of stars. We show that average asteroseismic parameters derived from these can be used to distinguish the stellar evolutionary state between RGB and RC stars without having to measure the often difficult dipole modes. Furthermore, we show how the fitting of some of these dipole modes can improve the detectability of acoustic glitches arising from the helium II ionization zone and how this can potentially be used to constrain the helium content in the cluster. We also discuss some of the difficulties facing similar studies in the future, where it seems that detailed studies of star clusters are facing some difficult times ahead.
Inflammatory mediator polymorphisms associate with initial periodontitis in adolescents
Authors: Heikkinen Anna Maria , Kettunen Kaisa , Kovanen Leena , Haukka Jari , Elg Jessica , Husu Heidi , Tervahartiala Taina , Pussinen Pirkko , Meurman Jukka , Sorsa Timo 
Published: September 2016

AbstractSeveral studies have addressed cytokine gene polymorphisms and their possible associations with periodontitis. We examined the association between salivary anti‐ and pro‐inflammatory mediator polymorphisms and initial periodontitis in Finnish adolescents, taking into account the effect of smoking. Salivary samples of 93 clinically examined adolescents from Eastern Finland were analyzed. Their oral health and smoking habits were recorded. Periodontal probing depth (PPD), and bleeding on probing (BOP) at four sites per tooth, root calculus (RC), and visible plaque index (VPI) were recorded from the index teeth. Salivary MMP‐8 median values were assessed. The sites with ≥4 mm PD were categorized as follows: PPD1 = one or more ≥4 mm pocket, PPD2 = two or more ≥4 mm pockets, and PPD3 = three or more ≥4 mm pockets. Genomic DNA was extracted from 300 μl of the saliva samples by genomic QIAamp® DNA Blood Mini Kit and genotyped for polymorphisms. Genetic variants for genotyping were selected from the following genes of interest: S100A8, FCGR2A, FCGR2B, IL10, MMP8, MMP3, MMP13, VDR, TLR4, MMP2, MPO, ELANE, IL1A, IL1B, IL1RN, CD28, MMP9, DDX39B, NFKBIL1, LTA, TNF, SOD2, IL6, TLR4, TIMP1, and SYN1. After false discovery rate control (FDR), polymorphisms in MMP3 (rs679620, rs520540, rs639752), CD28 (rs3116496), and VDR (rs2228570) associated (FDR q < 0.05) with deepened periodontal pockets. Smoking did not affect the results. Genetic polymorphisms of pro‐inflammatory mediators MMP3, CD28, and VDR seem to link to initial periodontitis.
Development of an automated method of detecting stereotyped feeding events in multisensor data from tagged rorqual whales
Authors: Allen Ann N. , Goldbogen Jeremy A. , Friedlaender Ari S. , Calambokidis John 
Published: September 2016

AbstractThe introduction of animal‐borne, multisensor tags has opened up many opportunities for ecological research, making previously inaccessible species and behaviors observable. The advancement of tag technology and the increasingly widespread use of bio‐logging tags are leading to large volumes of sometimes extremely detailed data. With the increasing quantity and duration of tag deployments, a set of tools needs to be developed to aid in facilitating and standardizing the analysis of movement sensor data. Here, we developed an observation‐based decision tree method to detect feeding events in data from multisensor movement tags attached to fin whales (Balaenoptera physalus). Fin whales exhibit an energetically costly and kinematically complex foraging behavior called lunge feeding, an intermittent ram filtration mechanism. Using this automated system, we identified feeding lunges in 19 fin whales tagged with multisensor tags, during a total of over 100 h of continuously sampled data. Using movement sensor and hydrophone data, the automated lunge detector correctly identified an average of 92.8% of all lunges, with a false‐positive rate of 9.5%. The strong performance of our automated feeding detector demonstrates an effective, straightforward method of activity identification in animal‐borne movement tag data. Our method employs a detection algorithm that utilizes a hierarchy of simple thresholds based on knowledge of observed features of feeding behavior, a technique that is readily modifiable to fit a variety of species and behaviors. Using automated methods to detect behavioral events in tag records will significantly decrease data analysis time and aid in standardizing analysis methods, crucial objectives with the rapidly increasing quantity and variety of on‐animal tag data. Furthermore, our results have implications for next‐generation tag design, especially long‐term tags that can be outfitted with on‐board processing algorithms that automatically detect kinematic events and transmit ethograms via acoustic or satellite telemetry.
Tree species diversity promotes aboveground carbon storage through functional diversity and functional dominance
Authors: Mensah Sylvanus , Veldtman Ruan , Assogbadjo Achille E. , Glèlè Kakaï Romain , Seifert Thomas 
Published: September 2016

AbstractThe relationship between biodiversity and ecosystem function has increasingly been debated as the cornerstone of the processes behind ecosystem services delivery. Experimental and natural field‐based studies have come up with nonconsistent patterns of biodiversity–ecosystem function, supporting either niche complementarity or selection effects hypothesis. Here, we used aboveground carbon (AGC) storage as proxy for ecosystem function in a South African mistbelt forest, and analyzed its relationship with species diversity, through functional diversity and functional dominance. We hypothesized that (1) diversity influences AGC through functional diversity and functional dominance effects; and (2) effects of diversity on AGC would be greater for functional dominance than for functional diversity. Community weight mean (CWM) of functional traits (wood density, specific leaf area, and maximum plant height) were calculated to assess functional dominance (selection effects). As for functional diversity (complementarity effects), multitrait functional diversity indices were computed. The first hypothesis was tested using structural equation modeling. For the second hypothesis, effects of environmental variables such as slope and altitude were tested first, and separate linear mixed‐effects models were fitted afterward for functional diversity, functional dominance, and both. Results showed that AGC varied significantly along the slope gradient, with lower values at steeper sites. Species diversity (richness) had positive relationship with AGC, even when slope effects were considered. As predicted, diversity effects on AGC were mediated through functional diversity and functional dominance, suggesting that both the niche complementarity and the selection effects are not exclusively affecting carbon storage. However, the effects were greater for functional diversity than for functional dominance. Furthermore, functional dominance effects were strongly transmitted by CWM of maximum plant height, reflecting the importance of forest vertical stratification for diversity–carbon relationship. We therefore argue for stronger complementary effects that would be induced also by complementary light‐use efficiency of tree and species growing in the understory layer.