bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mathematical and finite element analysis estimations of the reinforcement effect on Young's modulus of polymer membrane/montmorillonite clay nanocomposites
Authors: Santiago Arlette A. , Vargas Joel , Pérez Luis , Corona‐García Carlos , Alfonso Ismeli 
Published: February 2021

AbstractThis work attempts to estimate the effect of the reinforcement percentage on Young's modulus for membranes of polymer‐clay nanocomposites (PCNs). Models tried to simulate different contents of the reinforcement for experimentally obtained PCNs with nanometric montmorillonite clays (MMT) incorporated into a polynorbornene dicarboximide matrix. The analyses were carried out modeling through discrete element method (DEM) and finite element analysis (FEA) volume fractions from 0.01 to 0.025 of elliptical MMT nano‐platelets with aspect ratios = 0.2 (1000 × 500 nm) and thicknesses of 1 nm. These models were generated using as starting point the morphology and distribution of the reinforcements observed in scanning electron microscopy for experimental PCNs. Estimations were compared to predictions obtained by Rule of Mixtures and other mathematical models. Results showed that the elastic modulus of the nanocomposites significantly rises as MMT volume fraction increases. Besides, the use of DEM‐FEA generated the predictions closest to the experimental values, with relative errors lower than 10%. For the other models, the errors were significantly high, even reaching 100%. This shows the importance of DEM‐FEA to obtain a more accurate model of a real composite and a better estimation of its mechanical behavior.
Development and validation of the reading motivation questionnaire in an English as a foreign language context
Authors: Wang Wenjiao , Gan Zhengdong 
Published: February 2021

AbstractThis paper presents the development and validation of the reading motivation questionnaire in an English as a foreign language context (RMQ‐EFL) with Chinese secondary students. Data were collected from a sample of 293 secondary students in grades 10–11. Exploratory and confirmatory factor analyses resulted in determination of five factors (i.e.,reading efficacy, reading enjoyment, recognition, involvement, andcompliance) with a strong psychometric basis. The significant correlations between these five RMQ‐EFL factors and students' learning strategies in reading and between the five RMQ‐EFL factors and students' English learning achievements further confirmed the concurrent and predictive validity of the RMQ‐EFL. In addition, this study found that there were no significant differences in students' EFL reading motivation across gender and grade levels. The RMQ‐EFL can be used both as an evaluation tool for teachers to assess students' EFL reading motivation, and as a research tool for researchers to explore the relationships between students' English reading motivation and their English reading behavior and performance or to assess the effectiveness of targeted reading motivation interventions.
High‐Precision Density Measurements of Energetic Materials for Quality Assessment
Authors: Herrmannsdörfer Dirk , Klapötke Thomas M. 
Published: February 2021

AbstractEven though helium pycnometry is considered a very precise method of density determination, its use to analyse factors influencing crystal quality (e. g. solvent inclusions, amorphous states, crystal defects…) is limited due to the unknown inherent accuracy of the method. Previous studies have attempted to identify the best possible accuracy of helium pycnometry. However, no robust method has been proposed to validate even the precision obtained. This means that the often occurring, seemingly random density deviations have never been satisfactorily explained. In this study the influencing factors on density measurements of the CL‐20/HMX cocrystal and phase stabilised ammonium nitrate carried out with an AccuPyc 1340 TEC were quantified and a robust method of data analysis was developed to judge with certainty the quality and significance of the data obtained. This study shows that statistical tests such as the t‐test and ANOVA cannot be utilised to differentiate between samples or repeat measurements, even though the density data points exhibit a normal distribution. By utilising confidence intervals and quantifying the three major sources of error (sampling error, change in barometric pressure during the measurement, and weight in error), a repeatability of 0.015 % was achieved and a method was developed that enables differentiation between samples with a certainty as good as 0.05 %.
Integration of wavelet decomposition and artificial neural network for failure prognosis of reciprocating compressors
Authors: Lu Yen‐Ju , Wang Chen‐Hua 
Published: February 2021

AbstractCompressors in petrochemical plants are often crucial to process operations, and when a failure occurs, the outcome can be catastrophic. Many researches have been attempting to detect failure modes as early as possible to plan upfront repair and conceivably reduce maintenance time. A reciprocating compressor was selected as the target of this study, and a few years of historical records of maintenance parameters and maintenance work orders were gathered for analysis. The time history was divided into 13 events, and each event started with a normal operation and ended with a repair work order. Time‐domain features and wavelet decomposition features of the parameters were extracted, and the patterns stored within each event were identified using the artificial neural network and support vector machine. Moreover, a set of reasoning algorithms were developed to detect anomalies, and responsible failure modes were identified. For a specific type of compressor, the vibration signal was found to be related to most of the anomalies and thus used for evaluation. Results showed a >90% detection rate for failure mode diagnosis based on historical test data.
Optimal designs for dual response systems for the normal and binomial case
Authors: Burke Sarah E. , Montgomery Douglas C. , Anderson‐Cook Christine M. , Silvestrini Rachel T. , Borror Connie M. 
Published: February 2021

AbstractMost research in design of experiments focuses on appropriate designs for a system with just one type of response, rather than multiple responses. In a decision‐making process, relying on only one objective can lead to oversimplified, suboptimal choices that ignore important considerations. Consequently, the problem of constructing a design for an experiment when multiple types of responses are of interest often does not have a single definitive answer, particularly when the response variables have different distributions. Each of these response distributions imposes different requirements on the experimental design. Computer‐generated optimal designs are popular design choices for less standard scenarios where classical designs are not ideal. This work presents a new approach to experimental designs for dual‐response systems. The normal and binomial distributions are considered as potential responses. Using the D‐criterion for the linear model and the Bayesian D‐criterion for the logistic regression model, a weighted criterion is implemented in a coordinate‐exchange algorithm. Designs are evaluated and compared across different weights. The sensitivity of the designs to the priors supplied for the Bayesian D‐criterion is also explored.
Evaluation of a quick one‐step sample preparation method for the determination of the isotopic fingerprint of rapeseed (Brassica napus): Investigation of the influence of the use of 2,2‐dimethoxypropane on compound‐specific stable carbon and hydrogen isotope analyses by gas chromatography combustion/pyrolysis isotope ratio mass spectrometry
Authors: Xia Lili , Sakaguchi‐Söder Kaori , Stanojkovski Daniel , Schebek Liselotte 
Published: February 2021

RationaleGas chromatographic analyses for vegetable oils require transesterification, which generally involves multiple steps, mainly to generate fatty acid methyl esters (FAMEs). A quick method based on acid‐catalyzed transesterification using 2,2‐dimethoxypropane (DMP) enables the conversion in one step, in a single reactor. For compound‐specific stable carbon and hydrogen isotope analyses (C‐ and H‐CSIA) of individual fatty acids (FAs) in oil, the verification of this one‐step method has not yet been reported.MethodsIn this study, we evaluated the feasibility of the one‐step method for C‐ and H‐CSIA of individual FAMEs in rapeseed samples. The focus was on the investigation of the influence of methanol, which was produced from the reactions of DMP with glycerol and water during transesterification, on the accuracy of isotope composition of FAMEs, consequently of the FAs. The reproducibility of the one‐step method was assessed by the measurement of the FAMEs from rapeseed and rapeseed oil. For the C‐ and H‐CSIA of individual FAMEs, a gas chromatography combustion/pyrolysis isotope ratio mass spectrometry system was used.ResultsOur results showed that no significant differences arise in the carbon and hydrogen isotope compositions of the selected main FAMEs produced with and without DMP except for the H‐CSIA value of C18:3. The reproducibility of the one‐step method for rapeseed was in the range of ±0.1 mUr to ± 0.3 mUr for C‐CSIA and ±1 mUr to ±3 mUr for H‐CSIA of the main FAMEs.ConclusionsDMP improves the transesterification efficiency without influencing the accuracy of the C‐ and H‐CSIA of FAMEs. The performance of the one‐step method for rapeseed samples for the determination of C‐ and H‐CSIA values of FAMEs is satisfactory. Thus, the applicability of the one‐step method for isotopic fingerprint analyses of FAs in oilseeds is reported for the first time.
A symplectic indirect approach for a class of nonlinear optimal control problems of differential‐algebraic systems
Authors: Shi Boyang , Peng Haijun , Wang Xinwei , Zhong Wanxie , Gao Lingchong , Fottner Johannes 
Published: February 2021

AbstractDifferential‐algebraic equations (DAEs) can model constrained dynamical systems and processes from practical engineering. Therefore, research on nonlinear optimal control problems of DAEs is of theoretical significance for optimal control of constrained systems, which can generate reference trajectories and control inputs for online control strategies. In terms of the numerical solution of this type of problem, research on indirect numerical methods is still insufficient and less research focuses on symplectic‐preserving methods. In this article, a symplectic indirect approach is proposed for optimal control problems subject to index‐1 DAEs. Necessary conditions of the optimal control problem constitute a Hamiltonian boundary value problem (HBVP) and there exists a symplectic structure in the Hamiltonian system. In the proposed approach, based on specified properties of generating functions, discrete equations can preserve the symplectic structure of the Hamiltonian system. In the iterative solution, the Jacobian matrices of the discrete equations are sparse and symmetric, which are very significant to save memory and improve efficiency in practical computation. In numerical examples, the proposed approach can provide highly accurate state variables and control inputs with fewer iterations. More accurate cost functional can be obtained. Problems from the chemistry process also can be solved effectively, it verifies the problem‐solving ability of the proposed approach.
Finite‐time attitude tracking control and vibration suppression for flexible spacecraft
Authors: Zhu Wanwan , Zong Qun , Dou Liqian , Tian Bailing , Liu Wenjing 
Published: February 2021

AbstractIn this paper, an adaptive multivariable continuous terminal sliding mode (CTSM) controller with robust input shaper (RIS) is proposed for flexible spacecraft under model uncertainty and external disturbance. Firstly, for the problem of flexible vibration introduced by flexible appendage, the RIS based on disturbance observer is designed. The proposed input shaper can eliminate the flexible vibration effectively even if there are some disturbances in flight. Then, an adaptive multivariable CTSM controller is proposed for attitude tracking of flexible spacecraft, using only information about the output and its first derivative. The features of the developed methods are that it is continuous multivariable controller which attenuates the chattering effectively and the attitude tracking can be achieved in finite time. The stability and robustness properties of the system are proven using Lyapunov function. Finally, some numerical simulations are performed to validate the efficiency of the developed algorithm.
What to do about #MeToo? Consent, autonomy, and restorative justice: A case study
Authors: Sikka Tina 
Published: February 2021

AbstractThis article asks: Is it possible to craft a form of engaged, anti‐carceral, feminist political practice that carves out a space for sexual negotiation, exploration, sex positivity, and changing conceptions of consent in an era shaped by hypermediation and, for the purposes of this paper, #MeToo? Five British based academics working in the areas of sexuality studies, law, media studies, and sociology were interviewed on this topic so as to better understand contemporary scholarly attitudes and where current research stands. Each scholar was asked a series of questions around consent as a legal and normative regulator of sexual relations—including its drawbacks, their views on other models of consent—including communicative consent, embodied consent, sexual autonomy—the possibilities for alternative forms of justice, inclusive of prison abolition and restorative justice as they relate to sexual violence, and the kinds of feminism(s) they see developing from this.
Achieving Ultralow, Zero, and Inverted Tunneling Attenuation Coefficients in Molecular Wires with Extended Conjugation
Authors: Lee Hyun Ju , Cho Soo Jin , Kang Hungu , He Xin , Yoon Hyo Jae 
Published: February 2021

AbstractMolecular tunnel junctions are organic devices miniaturized to the molecular scale. They serve as a versatile toolbox that can systematically examine charge transport behaviors at the atomic level. The electrical conductance of the molecular wire that bridges the two electrodes in a junction is significantly influenced by its chemical structure, and an intrinsically poor conductance is a major barrier for practical applications toward integrating individual molecules into electronic circuitry. Therefore, highly conjugated molecular wires are attractive as active components for the next‐generation electronic devices, owing to the narrow highest occupied molecular orbital–lowest occupied molecular orbital gaps provided by their extended π‐building blocks. This article aims to highlight the significance of highly conductive molecular wires in molecular electronics, the structures of which are inspired from conductive organic polymers, and presents a body of discussion on molecular wires exhibiting ultralow, zero, or inverted attenuation of tunneling probability at different lengths, along with future directions.
Endemic earliest Lochkovian species ofCaudicriodus(conodont) from southern Laurentia and the Silurian–Devonian boundary
Authors: Barrick James E. , Sundgren Joshua R. , McAdams Neo E.B. 
Published: February 2021

AbstractTwoCaudicriodusspecies from lowermost Devonian strata in southern Laurentia (Texas–Oklahoma–Western Tennessee),C. anitaesp. nov. andC. murphyisp. nov., are endemic forms that appeared during the positive δ13C excursion associated with the Klonk Event. The otherCaudicriodusspecies that occur during the Klonk Event and that are often used to recognize the base of the Devonian,C. hesperiusandC. woschmidti, differ in that the I elements of the southern Laurentia species possess a middle row of nodes on the transverse ridges of the spindle. The apparatus ofC. murphyisp. nov. possesses three groups of elements in addition to the I element: F elements (short wide coniforms); D elements (denticles on the posterior margin) and C elements (slender coniforms with basally flaring costae). Strong provinciality in slightly younger LochkovianCaudicriodusspecies was demonstrated earlier, and we propose thatCaudicriodusspecies radiated independently into endemic species in different geographic regions just before or during the Klonk Event. A form originally described asC. woschmidti hesperiusby Simpson (1998) is reinterpreted as a late Ludlow–Pridoli species ofPraeicriodus, P. simpsonisp. nov., with an I element and apparatus structure probably ancestral toCaudicriodus.
Population genomic structure of Eurasian and African foxtail millet landrace accessions inferred from genotyping‐by‐sequencing
Authors: Hunt Harriet V. , Przelomska Natalia A. S. , Campana Michael G. , Cockram James , Bligh H. Frances J. , Kneale Catherine J. , Romanova Olga I. , Malinovskaya Elena V. , Jones Martin K. 
Published: February 2021

AbstractFoxtail millet [Setaria italica (L.) P. Beauv.] is the second most important millet species globally and is adapted to cultivation in diverse environments. Like its wild progenitor, green foxtail [S. viridis (L.) P. Beauv.], it is a model species for C4 photosynthetic pathways and stress tolerance genes in related bioenergy crops. We addressed questions regarding the evolution and spread of foxtail millet through a population genomic study of landraces from across its cultivated range in Europe, Asia, and Africa. We sought to determine population genomic structure and the relationship of domesticated lineages relative to green foxtail. Further, we aimed to identify genes involved in environmental stress tolerance that have undergone differential selection between geographical and genetic groups. Foxtail millet landrace accessions (n = 328) and green foxtail accessions (n = 12) were sequenced by genotyping‐by‐sequencing (GBS). After filtering, 5,677 single nucleotide polymorphisms (SNPs) were retained for the combined foxtail millet−green foxtail dataset and 5,020 for the foxtail millet dataset. We extended geographic coverage of green foxtail by including previously published GBS sequence tags, yielding a 4,515‐SNP dataset for phylogenetic reconstruction. All foxtail millet samples were monophyletic relative to green foxtail, suggesting a single origin of foxtail millet, although no group of foxtail millet was clearly the most ancestral. Four genetic clusters were found within foxtail millet, each with a distinctive geographical distribution. These results, together with archaeobotanical evidence, suggest plausible routes of spread of foxtail millet. Selection scans identified nine candidate genes potentially involved in environmental adaptations, particularly to novel climates encountered, as domesticated foxtail millet spread to new altitudes and latitudes.
Going Nuts for Words: Recommendations for Teaching Young Students Academic Vocabulary
Authors: Zucker Tricia A. , Cabell Sonia Q. , Pico Danielle L. 
Published: February 2021

AbstractDeveloping young children's vocabulary is essential for later reading success; thus, early childhood classrooms require a comprehensive vocabulary approach that teaches academic vocabulary. Yet even providing young children with child‐friendly definitions of sophisticated words can be a challenge. First, the authors outline the components of a comprehensive vocabulary program for young children. Second, they review research evidence on the importance of direct vocabulary instruction and ways to increase children's word consciousness and interest in learning “amazing” academic words. Next, they turn to practical suggestions of ways to select and teach new vocabulary. They describe ways to increase word consciousness that extend excitement for word learning. Finally, they demonstrate that early childhood educators can improve the quantity and quality of their vocabulary instruction when using a comprehensive vocabulary program the features routine shared book reading, direct vocabulary instruction, and supports for word consciousness.
Comparison of liberal and goal‐directed fluid therapy after small intestinal surgery for strangulating lesions in horses
Authors: Giusto Gessica , Vercelli Cristina , Gandini Marco 
Published: February 2021

AbstractBackground: There are few guidelines for the appropriate mode of fluid administration during and after colic surgery, and is challenging to reach the right balance while avoiding overhydration. This study aimed to compare goal‐directed fluid therapy (GDFT) and ‘liberal’ fluid regimens (LFRs) in horses undergoing small intestinal surgery.Methods: Eighteen horses subjected to small intestinal surgery were matched according to the surgical lesion, type of anastomosis, length of resection, and duration of clinical signs. Horses in the LFR group were administered intravenous (IV) fluids for at least 24 h. In the GDFT group, IV fluids were administered only when considered necessary based on clinical parameters. Postoperative reflux (POR), packed cell volume, total protein, heart rate, venous lactate level, complications, and long‐term survival rates were compared.Results: Three horses in the LFR and one in the GDFT group developed POR. Horses in the GDFT group had a shorter time interval to first oral water intake and shorter hospitalisation time. Postoperative complication rates and survival were not different between groups.Conclusion: Further studies are necessary to set guidelines for the evaluation of hydration status and to plan postoperative fluid administration; however, GDFT may be a valid alternative to liberal fluid therapy after colic surgery.
On the reinterpretation of non-resonant searches for Higgs boson pairs
Authors: Carvalho Alexandra , Goertz Florian , Mimasu Ken , Gouzevitch Maxime , Aggarwal Anamika 
Published: February 2021

Abstract
The detection of production of a pair of Higgs bosons before the end of LHC operation would be a clear evidence of New Physics (NP). As searches for non-resonant production of Higgs pairs are being designed it is of particular importance to be able to conveniently present current experimental results in terms of limits in the most ‘model-independent’ fashion possible. To this end, in this article we provide an analytic parametrization of the differential Higgs-pair production at the LHC in the effective field theory (EFT) extension of the SM. It results from a fit to the theory prediction for the gg → hh cross section at the 13 TeV LHC. Subsequently the resulting formula is used for a reweighing technique that allows to recast exclusion bounds from ATLAS and CMS hh →$$ \gamma \gamma b\overline{b} $$
γγb

b
¯

searches to any point of the considered EFT parameter space. We demonstrate with a fast simulation of the LHC detectors that with this approach it is possible to cover the continuous EFT parameter space, taking correctly into account the efficiencies of signal selections, without the necessity of rerunning a large number of full detector simulations. Finally, the resulting exclusion bounds are confronted with several explicit models, such as setups with additional scalars, including 2HDM, vector-like fermions, and minimal composite Higgs models, which are mapped to the EFT.