bluuebunny/crossref_metadata_2025_split huggingface dataset:
Google Trends and the forecasting performance of exchange rate models
Authors: Bulut Levent 
Published: November 2017

AbstractIn this paper, we use Google Trends data for exchange rate forecasting in the context of a broad literature review that ties the exchange rate movements with macroeconomic fundamentals. The sample covers 11 OECD countries’ exchange rates for the period from January 2004 to June 2014. In out‐of‐sample forecasting of monthly returns on exchange rates, our findings indicate that the Google Trends search query data do a better job than the structural models in predicting the true direction of changes in nominal exchange rates. We also observed that Google Trends‐based forecasts are better at picking up the direction of the changes in the monthly nominal exchange rates after the Great Recession era (2008–2009). Based on the Clark and West inference procedure of equal predictive accuracy testing, we found that the relative performance of Google Trends‐based exchange rate predictions against the null of a random walk model is no worse than the purchasing power parity model. On the other hand, although the monetary model fundamentals could beat the random walk null only in one out of 11 currency pairs, with Google Trends predictors we found evidence of better performance for five currency pairs. We believe that these findings necessitate further research in this area to investigate the extravalue one can get from Google search query data.
Superiorly based facial artery musculomucosal flap: A versatile pedicled flap
Authors: Berania Ilyes , Lavigne François , Rahal Akram , Ayad Tareck 
Published: November 2017

AbstractBackgroundThe superiorly based facial artery musculomucosal (FAMM) flap is pedicled on the angular artery. This flap offers a well‐vascularized mucosal surface allowing closure of medium size defects, most frequently within the oral cavity and intranasal region.MethodsWe describe a superiorly based harvest of the FAMM flap, which may be used for closure of multiple head and neck surgical defects. An operative technique video is provided, which can be viewed online.ResultsOur results demonstrate a fast and relatively straightforward harvest technique of the FAMM flap. This intraoral flap is a useful reconstructive tool, which also has the advantage to leave no visible external scars.ConclusionThe superiorly pedicled FAMM flap is a versatile and effective technique that may be integrated in the algorithm for reconstruction of head and neck defects.
Influence of the South Pacific decadal variability on Southeast China rainfall during boreal autumn
Authors: Li Gang , Chen Jiepeng , Wang Xin , Tan Yanke 
Published: November 2017

ABSTRACTUsing observational data and numerical experiments, the decadal relationship between South Pacific and rainfall over southeastern China during boreal autumn is examined. In the observational analyses, it is found that the boreal autumn South Pacific shows significant decadal variability with a significant periodicity of 11–21 years from 1960 to 2000, which is an independent phenomenon in the whole Pacific. This South Pacific decadal variability can induce significant decadal variability of boreal autumn rainfall over southeastern China. When the boreal autumn South Pacific decadal variability is in its positive phase, less rainfall appears over the southeastern China, and vice versa. The possible physical mechanisms are further investigated. It is suggested that the negative sea surface temperature anomalies (SSTA) in the extratropical South Pacific associated with positive phase of South Pacific decadal variability could result in an anomalous anticyclone to the east of Australia. The cross‐equatorial flow over the Maritime Continent and tropical western Pacific is enhanced under the influence of this anomalous anticyclone, favouring the location of western Pacific subtropical high moving more eastwards and then leading to the formation of anomalous cyclone over western North Pacific. To the west flank of this anomalous cyclone is the significantly anomalous northerly, which is favourable for less rainfall over southeastern China. On the other hand, significant negative SSTA appears in the Maritime Continent and tropical western Pacific could cause anomalous sinking motion here, which can further induce anomalous sinking motion over southeastern China through two meridional cells extending from Maritime Continent to southeastern China with a common rising branch over the southern South China Sea, thus resulting in less rainfall over southeastern China. Numerical experiments confirm our observational results.
Post‐Traumatic Heterotopic Ossification: An Old Problem in Need of New Solutions
Authors: Eisenstein Neil , Stapley Sarah , Grover Liam 
Published: November 2017

ABSTRACTHeterotopic ossification (HO) is the formation of pathological bone in ectopic sites and it can have serious consequences for functional outcomes. For many years, its main clinical relevance was as a rare complication of elective joint arthroplasty or CNS injury and a number of prophylaxes were developed to mitigate against it in these settings. As a consequence of changes in patterns of wounding and survival in conflicts since the turn of the century, post‐traumatic HO has become much more common and case severity has increased. It represents one of the main barriers to rehabilitation in a large cohort of combat‐injured patients. However, extant prophylaxes have not been shown to be effective or appropriate in this patient cohort. In addition, the lack of reliable early detection or means of predicting which patients will develop HO is another barrier to effective prevention. This review examines the current state of understanding of post‐traumatic HO including the historical context, epidemiology, pathophysiology, clinical issues, currently prophylaxis and detection, management, and potential future approaches. Our aims are to highlight the current lack of effective means of early detection and prevention of HO after major trauma and to stimulate research into novel solutions to this challenging problem. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1061–1068, 2018.
Characteristics of the water footprint of rice production under different rainfall years in Jilin Province, China
Authors: Li Hongying , Qin Lijie , He Hongshi 
Published: November 2017

AbstractBACKGROUNDRice is a special crop, and its production differs from that of other crops because it requires a thin layer of water coverage for a long period. The calculation of the water footprint of rice production should differ from that of other crops owing to the rice growing process. This study improved the calculation of blue and grey water footprints of rice production and analyzed the variations in the water footprints for rice production under different rainfall years in Jilin Province.RESULTSIn the drought year, the green water footprint was the lowest and the blue water footprint was the highest among the three years, while in the humid year, the green water footprint was the highest and the blue water footprint was not the lowest. The areas with higher water footprints were found in the east and west regions of Jilin Province, while the areas with lower water footprints were found in the middle east and middle regions of Jilin Province.CONCLUSIONBlue water was the primary water resource for rice production, although more precipitation provided the highest green water in the humid year; also, the spatial distributions of water footprints were not the same under different rainfall years. © 2017 Society of Chemical Industry
Copper(0) Mediated Single Electron Transfer Controlled Radical Polymerization toward CF Bonds on Poly(vinylidene fluoride)
Authors: Tan Shaobo , Zhang Yanan , Niu Zhijing , Zhang Zhicheng 
Published: November 2017

AbstractThe first copper(0) mediated controlled radical polymerization (CRP) of methyl methacrylate (MMA) toward CF bonds onto poly(vinylidene fluoride) (PVDF) is reported with rather high activity. By avoiding the halogen exchange, Cu0 instead of CuI complexes utilized as catalyst is responsible for the significantly improved polymerization activity. Using FH decoupled nuclear magnetic resonance technique, the grafting sites onto PVDF are finely located. From this, detailed topologic information including the grafting density, average length of each side chain, along with the overall grafted content of PMMA, is detected by tracking the polymerization as a function of time. This work offers not only a facile CRP strategy based on inactive CF bonds but also a deep insight into the cleavage of F‐bearing compounds in organic chemistry.
A new method of simulating volcanic eruption column formation and dispersion of ejected ash clouds
Authors: Arenal F. Espinosa , Avila R. , Raza S. S. 
Published: November 2017

ABSTRACTA new Eulerian−Lagrangian model is developed to predict the formation of eruption columns, and the long range transport and dispersion of volcanic ash clouds in the atmosphere. The model capability is tested by presenting the atmospheric dispersion of ash clouds released during two eruptions of the Popocatepetl volcano in Mexico. The atmospheric wind predictions were made by using the Eulerian regional atmospheric modelling system (RAMS), which is well tested over the Mexico region. Two Lagrangian models were also employed: (1) an eruption column formation model and (2) a Lagrangian stochastic deterministic (LSD) particle dispersion model. In a LSD model, the continuous plume is simulated by several puffs (clouds) successively released in the atmosphere. (1) The influence of the wind on the eruption column, (2) the transport and dispersion of the ash cloud and (3) the concentration of volcanic ash using a smoothed particle hydrodynamics technique are reported. This is thought to be a unique combination of mathematical prediction models and would be of interest to the broader scientific community. The formation of the eruption column is compared with ground observations, while the long range trajectory of the ash clouds is compared with images based on satellite data, qualitatively. In both cases the agreement within the observed and simulated plume shape was found to be satisfactory which indicated the suitability of the Eulerian wind prediction model (RAMS) in the region as well as that of Lagrangian models employed in the study.
Performance of various techniques in estimating missing climatological data over snowbound mountainous areas of Karakoram Himalaya
Authors: Kanda Neha , Negi H. S. , Rishi Madhuri S. , Shekhar M. S. 
Published: November 2017

ABSTRACTFilling gaps in climate data concerning mountainous areas with high spatial variability is significantly important since gaps tend to decrease the accuracy of trend estimation. In this study, the performance of seven classical methods in estimating missing values of maximum temperature, minimum temperature and precipitation at different time scales, i.e. daily (with different cases of missing data), weekly, biweekly and monthly, over Karakoram Himalaya was evaluated. Four performance indicators, i.e. mean absolute error, root mean squared error, co‐efficient of efficiency and skill score, were used to evaluate the relative performance of the methods; the mean absolute error was preferred over the other three measures for selecting the best method. The results indicate that multiple linear regression using the least absolute deviation criterion is best suited for estimation of all variables at all temporal scales except monthly precipitation data. It was also found that, for any variable, the deviation from the observed values decreased with increasing time step, i.e. there was more deviation on a daily scale than monthly.
An efficient sequence for fetal brain imaging at 3T with enhanced T1 contrast and motion robustness
Authors: Ferrazzi Giulio , Price Anthony N. , Teixeira Rui Pedro A.G. , Cordero‐Grande Lucilio , Hutter Jana , Gomes Ana , Padormo Francesco , Hughes Emer , Schneider Torben , Rutherford Mary , Kuklisova Murgasova Maria , Hajnal Joseph V. 
Published: November 2017

PurposeUltrafast single‐shot T2‐weighted images are common practice in fetal MR exams. However, there is limited experience with fetal T1‐weighted acquisitions. This study aims at establishing a robust framework that allows fetal T1‐weighted scans to be routinely acquired in utero at 3T.MethodsA 2D gradient echo sequence with an adiabatic inversion was optimized to be robust to fetal motion and maternal breathing optimizing grey/white matter contrast at the same time. This was combined with slice to volume registration and super resolution methods to produce volumetric reconstructions. The sequence was tested on 22 fetuses.ResultsOptimized grey/white matter contrast and robustness to fetal motion and maternal breathing were achieved. Signal from cerebrospinal fluid (CSF) and amniotic fluid was nulled and 0.75 mm isotropic anatomical reconstructions of the fetal brain were obtained using slice‐to‐volume registration and super resolution techniques. Total acquisition time for a single stack was 56 s, all acquired during free breathing. Enhanced sensitivity to normal anatomy and pathology with respect to established methods is demonstrated. A direct comparison with a 3D spoiled gradient echo sequence and a controlled motion experiment run on an adult volunteer are also shown.ConclusionThis paper describes a robust framework to perform T1‐weighted acquisitions and reconstructions of the fetal brain in utero. Magn Reson Med 80:137–146, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Mixed isogeometric analysis of strongly coupled diffusion in porous materials
Authors: Dortdivanlioglu B. , Krischok A. , Beirão da Veiga L. , Linder C. 
Published: November 2017

SummaryIn this paper, we develop a mixed isogeometric analysis approach based on subdivision stabilization to study strongly coupled diffusion in solids in both small and large deformation ranges. Coupling the fluid pressure and the solid deformation, the mixed formulation suffers from numerical instabilities in the incompressible and the nearly incompressible limit due to the violation of the inf‐sup condition. We investigate this issue using subdivision‐stabilized nonuniform rational B‐spline (NURBS) elements, as well as different families of mixed isogeometric analysis techniques, and assess their stability through a numerical inf‐sup test. Furthermore, the validity of the inf‐sup stability test in poromechanics is supported by a mathematical proof concerning the corresponding stability estimate. Finally, two numerical examples involving a rigid strip foundation on saturated soil and a swelling hydrogel structure are presented to validate the stability and to demonstrate the robustness of the proposed approach.
Integrating a micromechanical model for multiscale analyses
Authors: Zhao Chao‐Fa , Yin Zhen‐Yu , Hicher Pierre‐Yves 
Published: November 2017

SummaryThe Chang‐Hicher micromechanical model based on a static hypothesis, not unlike other models developed separately at around the same epoch, has proved its efficiency in predicting soil behaviour. For solving boundary value problems, the model has now integrated stress‐strain relationships by considering both the micro and macro levels. The first step was to solve the linearized mixed control constraints by the introduction of a predictor–corrector scheme and then to implement the micro–macro relationships through an iterative procedure. Two return mapping schemes, consisting of the closest‐point projection method and the cutting plane algorithm, were subsequently integrated into the interparticle force‐displacement relations. Both algorithms have proved to be efficient in studies devoted to elementary tests and boundary value problems. Closest‐point projection method compared with cutting plane algorithm, however, has the advantage of being more intensive cost efficient and just as accurate in the computational task of integrating the local laws into the micromechanical model. The results obtained demonstrate that the proposed linearized method is capable of performing loadings under stress and strain control. Finally, by applying a finite element analysis with a biaxial test and a square footing, it can be recognized that the Chang‐Hicher micromechanical model performs efficiently in multiscale modelling.
Multimaterial topology optimization with multiple volume constraints: Combining the ZPR update with a ground‐structure algorithm to select a single material per overlapping set
Authors: Zhang Xiaojia Shelly , Paulino Glaucio H. , Ramos Adeildo S. 
Published: November 2017

SummaryMultimaterial topology optimization often leads to members containing composite materials. However, in some instances, designers might be interested in using only one material for each member. Therefore, we propose an algorithm that selects a single preferred material from multiple materials per overlapping set. We develop the algorithm, based on the evaluation of both the strain energy and the cross‐sectional area of each member, to control the material profile (ie, the number of materials) in each subdomain of the final design. This algorithm actively and iteratively selects materials to ensure that a single material is used for each member. In this work, we adopt a multimaterial formulation that handles an arbitrary number of volume constraints and candidate materials. To efficiently handle such volume constraints, we employ the ZPR (Zhang‐Paulino‐Ramos) design variable update scheme for multimaterial optimization, which is based upon the separability of the dual objective function of the convex subproblem with respect to Lagrange multipliers. We provide an alternative derivation of this update scheme based on the Karush‐Kuhn‐Tucker conditions. Through numerical examples, we demonstrate that the proposed material selection algorithm, which can be readily implemented in multimaterial optimization, along with the ZPR update scheme, is robust and effective for selecting a single preferred material among multiple materials.
Approaches to improve the film ductility of colorless cycloaliphatic polyimides
Authors: Hasegawa Masatoshi , Fujii Mari , Wada Yuriko 
Published: November 2017

This study described approaches for improving the film ductility of colorless cycloaliphatic polyimides (PIs). An unexpected toughening effect was observed when a PI derived from pyromellitic dianhydride (PMDA) and 4,4′‐methylenebis(cyclohexylamine) was modified by copolymerization with a low isophoronediamine (IPDA) content of 5 to 30 mol%, despite there being no film‐forming ability in the homo PMDA/IPDA system. For example, at an IPDA content of 20 mol%, the copolymer showed significantly improved film toughness (maximum elongation at break, εb max = 57%), excellent optical transparency (light transmittance at 400 nm, T400 = 83.7%), and a high glass transition temperature (Tg = 317°C). This toughening effect can be interpreted on the basis of the concept of chain slippage. In this study, the PIs derived from bicyclo[2.2.2]octane‐2,3,5,6‐tetracarboxylic dianhydride (H‐BTA) with various diamines were also systematically investigated to evaluate the potential of H‐BTA‐derived systems. The combinations of H‐BTA with ether‐containing diamines led to highly tough PI films (εb max > 100%) with very high Tgs, strongly contrasting with the results of an earlier study. The observed excellent properties are related to the steric structure of H‐BTA. Our interest also extended to the solution processability. A copolyimide derived from H‐BTA with a sulfone‐containing diamine and an ether‐containing diamine achieved a very high optical transparency (T400 = 86.8%), a very high Tg (313°C), and good ductility (εb max = 51%) while maintaining solution processability. Thus, these approaches enabled us to dramatically improve the ductility of cycloaliphatic PI films that have, to date, been considered brittle.
Simultaneously improving the flame retardancy and mechanical properties for polyamide 6/aluminum diethylphosphinate composites by incorporating of 1,3,5‐triglycidyl isocyanurate
Authors: Ma Kun , Li Bin , Xu Miaojun 
Published: November 2017

The effect of 1,3,5‐triglycidyl isocyanurate (TGIC) as a synergistic agent on the fire retardancy, thermal, and mechanical properties for polyamide 6/aluminium diethylphosphinate (PA6/AlPi) composites were investigated in detail by limiting oxygen index; vertical burning (UL‐94); cone calorimeter; thermal gravimetric analysis; rheological measurements; and the tests of tensile, flexural, and Izod impact strength. The morphologies and chemical compositions of the char residue were investigated by scanning electron microscopy, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectra. The results demonstrated that AlPi and TGIC exerted an evident synergistic effect for flame retardant PA6 matrix, and the PA6/AlPi/TGIC composites with the thickness of 1.6 mm successfully passed UL‐94 V‐0 rating with the limiting oxygen index value of 30.8% when the total loading amount of AlPi/TGIC with the mass fraction of 97:3 was 11 wt%. However, the samples failed to pass the UL‐94 vertical burning tests when AlPi alone is used to flame retardant PA6 matrix with the same loading amount. The thermal gravimetric analysis data revealed that the introduction of TGIC promoted the char residue formation at high temperature. The rheological measurement demonstrated that the incorporation of TGIC improved the storage modulus, loss modulus, and complex viscosity of PA6/AlPi/TGIC composites comparing with that of neat PA6 and PA6/AlPi composites due to the coupling reaction between TGIC and the terminal groups of PA6 matrix. The morphological structures of char residues demonstrated that TGIC benefited to the formation of more homogenous and integrated char layer with no defects and holes on the surface comparing with that of PA6/AlPi composites during combustion. The higher melt viscosity of composites and the integrated and sealed char layer effectively inhibited the volatilization of flammable gas into the combustion zone and then led to the reduction of the heat release. The results of mechanical properties revealed that the incorporation of TGIC enhanced the mechanical properties for PA6/AlPi/TGIC composites comparing with that of PA6/AlPi composites with the same loading amount of flame retardant caused by the chain extension effect of TGIC. As a result, the flame retardancy and mechanical properties of PA6/AlPi composites simultaneously enhanced due to the introduction of TGIC.