bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel methodology to model the creep behavior of polymers at different temperatures
Authors: Kühl Andre , Polak Maria Anna 
Published: November 2021

AbstractA new methodology for modeling the creep behavior of polymers at different temperatures, by using phenomenological constitutive models, is presented in this paper. The viscoelastic model is given by a combination of springs and dashpots and is used to describe the nonlinear response of polymers, and the viscoplastic formulation is given by a power‐law equation. The approach proposed in this work is based on building master curves for different stress levels, and finding the dependency of the constitutive parameters with the temperature. After fitting the equations to the tensile creep tests at different temperatures, the final constitutive formulation is capable of modeling the behavior of polymers at any stress level and temperatures. Poly methyl metacrytale (PMMA) was used to investigate the accuracy of this proposal, and the results showed good agreement with the experimental data.
Detecting temporal anomalies with pseudo age groups: Homeownership in Canada, 1981 to 2016
Authors: Yuan Yue , Gu Jiaxin , Guo Xin , Zhu Yushu , Fu Qiang 
Published: November 2021

AbstractMethodological advances in demographic research, especially age‐period‐cohort (APC) analysis, primarily focus on developing new models yet often fail to consider practical concerns in empirical analysis. We propose a mixed approach that integrates multiple data imputation and structural change analysis in time series so that scholars can (i) construct pseudo age groups based on more coarsely grouped age data and (ii) identify temporal anomalies. This approach is illustrated using multiple waves of Canadian Population Census data (1981–2016). We construct pseudo age groups based on more coarse age information available in the Census data and identify a local anomaly in the temporal trajectory of homeownership in Canada's less populous provinces and territories. These findings are assessed and validated in comparison with results from more populous Canadian provinces. This research broadens the methodological repertoire for demographers, geographers, and social scientists in general and extends the literature on homeownership in an understudied area.
Features of atmospheric deep convection in northwestern South America obtained from infrared satellite data
Authors: Hernandez‐Deckers Daniel 
Published: November 2021

AbstractAtmospheric deep convection in equatorial continental regions is not homogeneously distributed in space or time, primarily due to surface inhomogeneities such as elevated topography and coastlines. This is the case in northwestern South America, which has particularly complex topography which, together with its geographical location, is responsible for some of the most prominent precipitation features around the globe. Although some of these features have been previously investigated in detail, others have not yet been studied, and some not even documented in the literature. The diverse atmospheric convective activity that takes place in this region constitutes a natural laboratory that can provide important insights into fundamental questions relevant for global climate. We use seven years of infrared brightness temperature data in 30 min intervals from the GOES‐13 geostationary satellite to estimate the spatial, seasonal and diurnal distributions of deep convective events in this region. By doing so, we bring forward several relevant features, providing a starting point for future investigations. For example, we find that deep convective events have a bimodal seasonal distribution throughout most of the Colombian Orinoco and Amazon basins, where precipitation is known to have a unimodal distribution. Furthermore, deep convective events in this region tend to be comparable in size to those offshore the Colombian Pacific coast or over the Magdalena river valley, but with significantly shorter lifetimes. On the other hand, nocturnal convection dominates at several continental locations; one of these, the middle‐lower Magdalena river valley, has been previously identified as one of the most active lightning hotspots on Earth, but its convective mechanisms have not yet been fully investigated. Another such location worth investigating is the middle Magdalena river valley, which may have strong similarities with the Maracaibo Lake area.
Room‐Temperature Solid‐State Quantum Emitters in the Telecom Range
Authors: Mu Zhao , Rasmita Abdullah , Yang Jianqun , Li Xingji , Gao Weibo 
Published: November 2021

AbstractBuilding a quantum network is the ultimate goal of quantum information science. Among the candidates to realize quantum node, quantum repeater, and quantum channel, the solid‐state emitters are particularly outstanding because of the presence of the spin‐photon interface. Some of the solid‐state emitters such as carbon nanotubes, color centers, transition metal ions, and rare earth ions can give telecom wavelength emission at room temperature. These emitters have different origins of single‐photon emission. Here, the basic properties of each kind of emitter and their progress towards applications are reviewed. This review also introduces the current efforts to improve the emitters’ brightness by integrating them into nanostructures.
Definition and analysis of stability margins for a class of nonlinear systems
Authors: Das Siddharth Sankar , Shtessel Yuri , Zhang Cheng , Plestan Franck 
Published: November 2021

AbstractIn this article, phase and gain stability margins are defined and studied for a class of nonlinear systems namely, the Lur'e type. The computation algorithms for practical phase and gain margin identification in such systems based on the describing function—harmonic balance technique, circle criterion, and Lyapunov methods involving linear matrix inequalities are presented. The efficacy of the proposed methodologies is validated on a case study.
Finite‐time and fixed‐time sliding mode control for discontinuous nonidentical recurrent neural networks with time‐varying delays
Authors: Aouiti Chaouki , Bessifi Mayssa 
Published: November 2021

AbstractThis article investigates the synchronization problem in finite‐time and fixed‐time of the drive‐response delayed recurrent neural networks (RNNs). Moreover, it is assumed that the parameters of the RNNs are nonidentical and the activation functions are discontinuous. For addressing the synchronization problem in finite‐time and fixed‐time, an improved sliding mode control (SMC) approach is presented. In a first time, by applying the drive‐response concept and the synchronization error between the drive‐response model, two novel integral sliding mode surfaces are constructed such that the synchronization error can converge to zero in finite‐time and fixed‐time. In second time, two SMC is created to overcome the finite‐time and fixed‐time synchronization problem of delayed RNNs. On the basis of Lyapunov stability theory, several sufficient criteria are obtained for the considered discontinuous nonidentical RNNs with time‐varying delays models to achieve finite‐time synchronization and fixed‐time synchronization. Moreover, two types of setting time, which are dependent and independent on the initial values, are given respectively. In the end, three numerical simulations are given to illustrate the effectiveness of the synchronization criteria.
System demonstrations of Ka‐band 5‐Gbps data transmission for satellite applications
Authors: Lu Fan , Jiang Yu , Wang Rui , Wang Hu , Zhao Pengfei , Wei Hongbo , Ma Bing , Ma Chao 
Published: November 2021

SummarySatellite‐ground‐link high‐rate high‐efficiency data transmission technique is one of the key supports for the development of high‐resolution low‐earth‐orbit (LEO) earth observation satellite systems. Ka‐band, frequency ranging from 24.6 to 40 GHz, shares a wide available bandwidth, high frequency reuse rate, and strong ability of anti‐jamming. Satellite operators have utilized the Ka‐band for satellite‐earth data transmission, which requires higher traffic capacity, and even have planned to launch new satellites with Ka‐band capacity. In this paper, we propose and experimentally demonstrate a 5‐Gbps uncoded data rate (corresponding to the channel rate of 6 Gbps) of Ka‐band data‐transmission system with dual‐circular polarization and frequency reuse for satellite‐earth applications. The objective of the experiment is gathering experimental data to validate the performance of the proposed four channel systems, including bit error ratio (BER) and link budget. Our work could support future satellite communication applications and meet the imperative demands of high rate transmission to earth.
Intense Blue Chromophores in Cobalt Doped Phenacite‐Type Zinc Germanate System through Jahn‐Teller Distortion of Co Tetrahedron
Authors: Raj Athira K. V. , Rao Padala Prabhakar 
Published: November 2021

AbstractIn the quest for new blue chromophores with less usage of cobalt alternatives to the carcinogenic and expensive zinc‐cobalt aluminate system, we developed cobalt doped phenacite type zinc germanate system. Rietveld analysis reveals that the CoO4 tetrahedron intensely experienced Jahn‐Teller distortions leading to irregular geometry on substitution. The UV‐vis‐IR absorption spectra exhibit intense Co2+ d‐d transitions with three fold splitting associated with the CoO4 tetrahedron in the visible and IR region, indicating low symmetry. The crystal field strength 10Dq, Racah parameter and Nephelauxetic ratio variations reflect on the improved covalency of the Co2+ environment. Thus the synergetic effect of Jahn‐Teller distortions and covalency of the CoO4 tetrahedron lead to strong absorptions in the green to red region resulting in intense blue colors with low cobalt content (2.2 to 8.9 mol %). The typical composition Zn1.6Co0.4GeO4 exhibits intense blue hue b*=−58.64, much higher than that of the commercial CoAl2O4 system.
One‐Pot Synthesis of α‐Aminonitriles in Water Using Iron (III) Tosylate Hexahydrate (Fe(OTs)3 ⋅ 6H2O) as a Green Catalyst
Authors: Dave Alpa Y. , Begari Eeshwaraiah 
Published: November 2021

AbstractAn efficient and environmentally friendly synthetic protocol has been presented to synthesize α‐aminonitriles from aldehydes, amines and trimethylsilyl cyanide using 10 mol% iron(III) tosylate hexahydrate (Fe(OTs)3 ⋅ 6H2O) as a green catalyst in aqueous media through one‐pot procedure. Iron(III) tosylate hexahydrate is a promising catalyst, introduced first time for the synthesis of α‐aminonitriles in aqueous media as it is commercially available, inexpensive, non‐toxic, operational simplicity and has a short reaction time with excellent yields is awaited to contribute to the development of novel green protocol for the synthesize α‐aminonitriles.
Substituted 2‐(ortho‐hydroxyaryl)cyclopenta[b]pyridines: Synthesis and Fluorescent Properties under Neutral, Acidic Medium and Solid State
Authors: Batalin Sergey D. , Golikova Margarita A. , Khrustaleva Alexandra A. , Bakal Artem A. , Ponomareva Tatyana S. , Goryacheva Irina Yu. 
Published: November 2021

AbstractNew derivatives of substituted 2‐(ortho‐hydroxyaryl)cyclopenta[b]pyridines were synthesized by pseudo‐five component reaction of cyclopentanone, two molecules of aromatic aldehyde, Kröhnke salt of ortho‐hydroxy substituted aromatic ketone and ammonium acetate. On the basis of the counter four‐component synthesis, the path of this transformation has been established. The fluorescent properties of the obtained structures are considered in chloroform under neutral, acidic conditions (TFA added) and in the solid state.
Multicomponent Synthesis, Crystal Structure, Hirshfeld Surface Analysis, and Molecular Docking of 4H‐Pyrans
Authors: Lalhruaizela  , Marak Brilliant N. , Sran Balkaran S. , Singh Ved Prakash 
Published: November 2021

AbstractIn this study, a series of four 4H‐pyrans were synthesized by multicomponent reaction, crystallized, and single‐crystal X‐ray diffraction was used to obtain their molecular geometries. The supramolecular assembly of the molecules through non‐covalent interactions was then studied and demonstrated. The weak intermolecular interactions in the molecular packing of compounds were further validated through Hirshfeld surface analysis. The synthesized compounds′ biological activity was predicted in Pass prediction. A molecular docking study was employed to validate its activity by analyzing its binding affinity and mode in the binding pocket of the beta‐adrenoreceptors (β1‐AR and β2‐AR). Results showed that ethyl 6‐amino‐5‐cyano‐2‐methyl‐4‐(2‐nitrophenyl)‐4H‐pyran‐3‐carboxylate have good antiischemic activity and binding affinity to both the adrenoreceptors. This study further demonstrated the importance of non‐covalent intermolecular interactions of 4H‐pyrans in the formation of supramolecular self‐assembly and contributions of weak interactions in binding affinity towards the target receptor. The studied compounds displayed distinctive intermolecular interactions of N−H…N, N−H…O hydrogen‐bonding patterns and C−H…π and π…π close contact interactions.
Graphene Oxide Supported Cubic ZnO for Enhanced Photodecomposition of Dyes
Authors: Wang Lianhuan , Sun Heyu , Ji Zhicheng , Zhang Dongdong , Zhao Yiping , Chen Li 
Published: November 2021

AbstractA new nanocomposites photocatalyst was fabricated including cubic zinc oxide (ZnO) and the graphene oxide (GO) by simple solvothermal method. The hexagonal ZnO nanoparticles with cubic shapes were acquired via calcination of zeolitic imidazolate framework‐8 (ZIF‐8) pyrolysis at 450 °C. The result of optical absorption property and photoelectrochemical performance showed that GO enhanced the photocatalytic performance of ZnO due to the enhanced visible light absorption, the fewer electron‐hole pairs recombine, the efficient transfer of electron‐hole pairs and effectively reduced the accumulation of ZnO. The ZnO‐GO nanocomposites photocatalyst was demonstrated remarkable degradation performance that almost completely degraded Rhodamine B (RhB) in 40 min and Methyl orange (MO) in 100 min under sunlight. It also exhibits good recyclability after 5 cycles that keep high photocatalytic efficiencies of 94 %. This kind of catalyst with photocatalytic activity and stable performance is expected to be widely used in the photocatalytic degradation of dyes, heavy metal ions, antibiotics and other fields.
Investigation of Indole‐3‐piperazinyl Derivatives as Potential Antidepressants: Design, Synthesis, In‐Vitro, In‐Vivo and In‐Silico Analysis
Authors: Kumar Ravi R. , Kumar Vijay , Kaur Dilpreet , Nandi Nilay K. , Dwivedi Ashish R. , Kumar Vinod , Kumar Bhupinder 
Published: November 2021

AbstractDepression is declared the second leading cause of disability worldwide. Recently, cases of depression have increased significantly in adolescents, young adults as well as in elder population. Monoamine oxidase‐A (MAO‐A) is considered one of the major targets for the treatment of depression. In the current study, we have designed and synthesized various indole functionalized piperazinyl derivatives and evaluated them for in vitro MAO‐A inhibitory activity and in vivo antidepressant‐like activity. Most of the compounds were found to possess potent MAO‐A inhibitory activity with IC50 values in the sub‐micromolar range along with significant selectivity over MAO‐B. Compounds RP1 and RP9 emerged as the most promising reversible MAO‐A inhibitors with IC50 values of 0.11±0.03 μM and 0.14±0.02 μM and displayed selectivity of 193 folds and 178 folds over Monoamine oxidase‐B (MAO‐B), respectively. In the series, RP1 showed good intracellular ROS inhibitory activity along with neuroprotective properties. These compounds were found nontoxic against SH‐SY5Y cells and explored antidepressant activities. In the in vivo Forced swimming test (FST) and Tail suspension test (TST) studies, RP1 exhibited potential antidepressant‐like behavior similar to standard drug fluoxetine while compound RP9 showed antidepressant‐like activity only in the TST studies. The molecular docking and dynamics studies further supported the results obtained in the in vitro and in vivo studies. Thus, the indole functionalized piperazinyl derivatives were found to be promising ligands and can be developed as new antidepressant molecules.
Porous Ga2O3 Nanotubes Derived from Urease‐Mediated Interfacially‐Grown NH4Ga(OH)2CO3 for High‐Efficient Hydrogen Evolution
Authors: Wang Ting , Wang Zheng‐Wu , Zhang Ye , Yang Xiao‐Ting , Zhu Yi‐Zhou , Wang He‐Fang 
Published: November 2021

AbstractThe authors proposed a novel template‐free strategy, urease‐mediated interfacial growth of NH4Ga(OH)2CO3 nanotubes at 20–50 °C, to fabricate the porous Ga2O3 nanotubes. The subtlety of the proposed strategy is all the products from urea enzymolysis are utilized in formation of NH4Ga(OH)2CO3 precipitates, and the key for interfacial growth of NH4Ga(OH)2CO3 nanotubes is the dynamic match between the rate of CO2 bubble fusion and NH4Ga(OH)2CO3 precipitation. The proposed strategy works well for the doped porous Ga2O3 nanotubes. As a proof‐of‐concept, the porous β‐Ga2O3 and β‐Ga2O3:Cr0.001 nanotubes are used as photocatalysts or co‐catalysts with Pt, for H2 evolution from water splitting. The H2 evolution rate of porous β‐Ga2O3 nanotubes reach 39.3 mmol g−1 h−1 with solar‐to‐hydrogen (STH) conversion efficiency of 2.11% (Hg lamp) or 498 µmol g−1 h−1 with STH of 0.03% (Xe lamp) respectively, both about 3 times of β‐Ga2O3 nanoparticles synthesized at pH 9.0 without urease. The Cr‐doping enhances the in‐the‐dark H2 evolution rate pre‐lighted by Hg lamp, and Pt co‐catalysis further elevates the H2 evolution rate, for instance, the H2 evolution rate of Pt‐loaded β‐Ga2O3:Cr0.001 nanotubes reaches 54.7 mmol g−1 h−1 with STH of 2.94% under continuous lighting of Hg lamp and 1062 µmol g−1 h−1 in‐the‐dark.
Linguistically Responsive Instruction in International Branch Campuses: Beliefs and Practices of Liberal Arts and STEM Instructors
Authors: Hillman Sara 
Published: November 2021

AbstractThis study proposes employing linguistically responsive instruction (LRI) in transnational higher education such as international branch campuses (IBCs). It sheds light on the beliefs and practices of content instructors teaching in English‐medium IBCs, in terms of supporting students’ academic language development. Previous studies have shown how content instructors, particularly in STEM fields, do not see teaching language as part of their role in the classroom and do not attach importance to it. However, students in IBC contexts often need more language support. 101 IBC instructors from various disciplines completed a survey regarding their beliefs about providing language support for students. A purposeful sampling of 6 engineering, science, and liberal arts instructors were also video‐recorded teaching their classes and then interviewed about LRI practices using stimulated‐recall techniques. Findings show that while STEM instructors tended to align less with LRI than liberal arts instructors on the surveys, they employed multiple LRI practices while observed teaching. The study shows the importance of going beyond just attitudinal surveys when it comes to understanding STEM instructors’ dispositions toward teaching language, and it is proposed that IBCs create dialogic, multidisciplinary faculty learning communities on academic language development and meaning making resources.
An Introduction to Structural Equation Modeling
Authors: Hair Joseph F. , Hult G. Tomas M. , Ringle Christian M. , Sarstedt Marko , Danks Nicholas P. , Ray Soumya 
Published: November 2021

AbstractStructural equation modeling is a multivariate data analysis method for analyzing complex relationships among constructs and indicators. To estimate structural equation models, researchers generally draw on two methods: covariance-based SEM (CB-SEM) and partial least squares SEM (PLS-SEM). Whereas CB-SEM is primarily used to confirm theories, PLS represents a causal–predictive approach to SEM that emphasizes prediction in estimating models, whose structures are designed to provide causal explanations. PLS-SEM is also useful for confirming measurement models. This chapter offers a concise overview of PLS-SEM’s key characteristics and discusses the main differences compared to CB-SEM. The chapter also describes considerations when using PLS-SEM and highlights situations that favor its use compared to CB-SEM.
Operator bases in effective field theories with sterile neutrinos: d ≤ 9
Authors: Li Hao-Lin , Ren Zhe , Xiao Ming-Lei , Yu Jiang-Hao , Zheng Yu-Hui 
Published: November 2021

Abstract
We obtain the complete and independent bases of effective operators at mass dimension 5, 6, 7, 8, 9 in both standard model effective field theory with light sterile right-handed neutrinos (νSMEFT) and low energy effective field theory with light sterile neutrinos (νLEFT). These theories provide systematical parametrizations on all possible Lorentz-invariant physical effects involving in the Majorana/Dirac neutrinos, with/without the lepton number violations. In the νSMEFT, we find that there are 2 (18), 29 (1614), 80 (4206), 323 (20400), 1358 (243944) independent operators with sterile neutrinos included at the dimension 5, 6, 7, 8, 9 for one (three) generation of fermions, while 24, 5223, 3966, 25425, 789426 independent operators in the νLEFT for two generations of up-type quarks and three generations of all other fermions.
Causality and gravity
Authors: Donoghue John F. , Menezes Gabriel 
Published: November 2021

Abstract
We show how uncertainty in the causal structure of field theory is essentially inevitable when one includes quantum gravity. This includes the fact that lightcones are ill-defined in such a theory. This effect is small in the effective field theory regime, where it is independent of the UV completion of the theory, but grows with energy and represents an unknown uncertainty for a generic UV completion. We include details of the causality uncertainty which arises in a particular UV completion, i.e. quadratic gravity. We describe how the mechanisms uncovered in the effective field theory treatment, and some of those in quadratic gravity, could be common features of quantum gravity.