bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significance of Hall effect on heat and mass transport of titanium alloy‐water‐based nanofluid flow past a vertical surface with IMF effect
Authors: Singh Jitendra Kumar , Kolasani Suneetha , Savanur Vishwanath 
Published: April 2021

AbstractIn this mathematical presentation, we examined the significance of Hall current on MHD buoyancy‐driven boundary layer flow of a Ti6Al4V‐H2O based nanofluid past a vertical surface implanted in a uniform permeable region. The vertical surface is considered to be magnetized and induced magnetic field (IMF) impacts are also considered. The nondimensional flow model is solved with the assistance of the two‐term perturbation scheme. Various results are obtained by numerical computation for different significant parameters. These results are presented and analyzed in graphical and tabular form. In the boundary layer domain, the transpiration velocity across the surface tends to diminish the main flow, IMF along the main flow, fluid temperature, and concentration. It is remarkably noted that IMF along the main flow grows for incrementing values of volume fraction coefficient of nanofluid. In the magnetic boundary layer domain, the main flow and IMF along the main flow grow with Hall current. Furthermore, it is seen that for the progressing values of magnetic Prandtl number, the main flow reduces while normal flow and IMF along the main flow is induced in the boundary layer domain.
A simple U‐shaped device with a superhydrophobic coating used to sort droplets by surface tension
Authors: Feng Rui , Li Xin‐Ming , Wang Lin , Li Wan‐Yuan , Zhang Yu‐Ping 
Published: April 2021

AbstractManipulation of droplets is an issue of great interest and challenge in microfluidics and chemical analysis domains. Herein, an ethanol suspension of beeswax and TiO2 (25 ± 5 nm), and SiO2 (7–40 nm) nanoparticles was sprayed on the surface of a self‐fabricated U‐shaped device. The resulted superhydrophobic coating enabled liquid droplets to roll back and forth in the groove of semicircular arc freely. According to the apparent difference of whole rolling distance, liquid droplets with less difference of surface tension were distinguished and sorted precisely. More importantly, the elegant analytical device was used to determine the surface tension for some typical food liquids and a relative error less than 5% was obtained, compared with the results measured by the contact angle goniometer. It could be used potentially as a simple, fast, and inexpensive diagnostic platform to sort liquid droplets and determine their surface tension values quantitatively.
Copper porphyrin‐catalyzed C(sp2)—O bond construction via coupling phenols with formamides
Authors: Yang Shuang , Chen Xiao‐Yan , Xiong Ming‐Feng , Zhang Hao , Shi Lei , Lin Dong‐Zi , Liu Hai‐Yang 
Published: April 2021

AbstractCopper porphyrin‐catalyzed construction of C(sp2)—O bond via coupling formamides with phenols was achieved firstly. A broad range of substrates afforded various carbamates in moderate to good yields with good functional group tolerance at low catalyst loading. Intermolecular competing kinetic isotope effect experiment indicated that the generation of formamide radical is the rate‐determining step of current cross‐dehydrogenative coupling (CDC) reaction. The research extends the application of metalloporphyrin in CDC reaction.
Self‐confidence as a predictor of senior dental student academic success
Authors: Meisha Dalia E. , Al‐dabbagh Raghad A. 
Published: April 2021

AbstractPurposeNoncognitive indicators, such as personality type and self‐confidence, have been used as predictors of achievement. Accordingly, we investigated whether self‐confidence in clinical skills predicts academic success among predoctoral senior dental students.MethodsTwo consecutive cohorts (N = 336) of predoctoral senior dental students were invited to rate their self‐confidence in clinical procedures twice: at the beginning and at the end of the academic year. Academic performance in clinical assessments was retrieved from scholastic records. Multiple linear regression models were constructed to predict clinical assessment grades using self‐confidence scores as a predictor after controlling for possible confounders.ResultsSelf‐confidence scores in clinical procedures were positively correlated with clinical and academic performance. Self‐confidence in clinical procedures and grade point averages were consistent predictors of student performance. Additionally, self‐confidence had improved at the end of the senior year (p = 0.003).ConclusionsSelf‐confidence in clinical procedures was a predictor of future clinical success. Therefore, fostering and nurturing the confidence of students and integrating self‐confidence assessment into the curricula at relevant timepoints should be a goal in dental education. Moreover, self‐assessment of confidence in clinical skills could be used to guide students and graduates in developing their own personal development plan.
Residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and its metabolites during tea growing and tea brewing
Authors: Bai Aijuan , Chen Ang , Chen Wuying , Liu Shaowen , Luo Xiangwen , Liu Yong , Zhang Deyong 
Published: April 2021

AbstractBACKGROUNDTolfenpyrad and dinotefuran are two representative pesticides used for pest control in tea gardens. Their application may bring about a potential risk to the health of consumers. Therefore, it is essential to investigate the residue behavior, transfer and risk assessment of tolfenpyrad, dinotefuran and metabolites from tea garden to teacup.RESULTSAn effective analytical method was established and validated to simultaneously determine tolfenpyrad, dinotefuran and its metabolites (DN and UF) in tea. The average recoveries of tolfenpyrad, dinotefuran, DN and UF were in the range 72.1–106.3%, with relative standard deviations lower than 11.8%. On the basis of the proposed method, the dissipation of tolfenpyrad and dinotefuran in fresh tea leaves followed first‐order kinetics models with half‐lives of 4.30–7.33 days and 4.65–5.50 days, respectively. With application amounts of 112.5–168.75 g a.i. ha–1 once or twice, the terminal residues of tolfenpyrad and total dinotefuran in green tea were lower than 19.6 and 7.13 mg kg−1, respectively, and below their corresponding maximum residue limits . The leaching rates of tolfenpyrad and total dinotefuran during the tea brewing were in the ranges 1.4–2.3% and 93.7–98.1%, respectively.CONCLUSIONTolfenpyrad and dinotefuran in tea were easily degraded. The RQc and RQa values for tolfenpyrad were 37.6% and 5.4%, which were much higher than for dinotefuran at 24.7% and 0.84%, respectively. The data indicated that there was no significant health risk in tea for consumers at the recommended dosages. The results provide scientific data regarding the reasonable use of tolfenpyrad and dinotefuran aiming to ensure safe tea consuption. © 2021 Society of Chemical Industry.
Breeding Habitat Associations of Eastern Whip‐Poor‐Wills in Managed Forests
Authors: SPILLER KIMBERLY J. , KING DAVID I. 
Published: April 2021

ABSTRACTPopulations of the eastern whip‐poor‐will (Antrostomus vociferus; whip‐poor‐will) have declined throughout most of its range, making it a species of high conservation concern in nearly every state and province where it occurs. Researchers have reported whip‐poor‐wills are associated with forest stands with open canopies, and thus silviculture may be a promising means for promoting their populations, yet the ecological literature does not quantify fine‐scale habitat relationships capable of assisting with silviculture prescriptions. Our objective was to quantify the associations between whip‐poor‐wills, canopy openness, and other vegetation characteristics to provide managers with guidance for whip‐poor‐will management. Based on prior research, we hypothesized that whip‐poor‐wills may be associated with intermediate levels of canopy retention and that their numbers would also be affected by understory characteristics. We surveyed whip‐poor‐wills with point counts in managed forest at the Fort Drum Army installation in New York, USA, during 2015 and 2016 and collected vegetation measurements at each point count location to relate whip‐poor‐will occupancy with vegetation structure and composition. Whip‐poor‐will occupancy was strongly related to intermediate levels of basal area, with peak occupancy at 13.8 m2/ha, a value that corresponds to forest denser than most shrublands but more open than closed‐canopy forest. Whip‐poor‐will presence was negatively related to understory height, which is consistent with prior studies. These findings provide managers with quantitative targets that can be used to increase or maintain whip‐poor‐will numbers and abundance of other disturbance‐associated species similarly unable to persist in unmanaged forests stands. © 2021 The Wildlife Society.
All‐Dielectric Fiber Meta‐Tip Enabling Vortex Generation and Beam Collimation for Optical Interconnect
Authors: Zhou Changyi , Lee Woo‐Bin , Gao Song , Li Hongliang , Park Chul‐Soon , Choi Duk‐Yong , Lee Sang‐Shin 
Published: April 2021

Abstract“Lab‐on‐fiber” technology, which combines the unique merits of optical fibers with nanophotonic platforms, has received significant investigation due to its profound ability to control light at the nanoscale, which has significantly boosted the functionalities of conventional fibers. Previous plasmonic‐based fiber meta‐tips (FMTs) have been inhibited by the intrinsic ohmic losses of the metallic structures, resulting in limited light manipulation efficiency. In addition, to become prominent candidates for integrated photonics, their functional diversity needs to be enhanced. In this study, an FMT constructed by tethering an all‐dielectric metasurface to a single‐mode fiber for bifunctional light manipulation is implemented. Distinct light manipulation, including vortex generation and beam collimation, is executed by tailoring the phase profiles encoded in the metasurface for transverse electric and transverse magnetic polarized light. To build the proposed FMT, a polarization‐selective metasurface is first created via lithography nanofabrication and then attached to an optical fiber with the aid of a vision system. Moreover, as a proof‐of‐concept, the feasibility of exploiting the established FMT for applications such as optical interconnects is demonstrated. The resulting fiber optics and metasurface‐based meta‐tip represent a major breakthrough in the lab‐on‐fiber technology roadmap for applications such as optical communication, optical trapping, and biological sensing.
Research Progress of All Organic Polymer Dielectrics for Energy Storage from the Classification of Organic Structures
Authors: Luo Jiaming , Mao Jiale , Sun Wenjie , Wang Shuang , Zhang Lei , Tian Liliang , Chen Yu , Cheng Yonghong 
Published: April 2021

AbstractDielectric films are the foundation of power electronic equipment for energy storage in capacitors. However, typical dielectric films exhibit undesirable energy storage density and thermal stability, limiting its further application in the advanced field. For both pure polymers and composites‐based dielectrics, the macromolecular matrix greatly determines the performances. This paper summarizes the research progress of all‐organic polymer materials for the dielectric application from the perspective of molecular structure design. Systematic comparisons on properties, including dielectric constant and dielectric loss, glass transition temperature, and energy density are given, expecting to inspire researchers to devote further efforts in this area. An outlook for the future of all‐polymer dielectrics is also presented.
Michael Polyaddition Approach Towards Sulfur Enriched Nonaromatic Polymers with Fluorescence‐Phosphorescence Dual Emission
Authors: Kausar Fahmeeda , Zhao Zihao , Yang Tianjia , Hou Wubeiwen , Li Yuxuan , Zhang Yongming , Yuan Wang Zhang 
Published: April 2021

AbstractNonaromatic photoluminescent polymers have attracted great attention due to their intriguing photophysical properties and promising implications in optoelectronic and biological areas. The luminescence from these nonconventional luminophores can be well rationalized by the clustering‐triggered emission mechanism. Sulfur, although as an n‐electron‐rich element with big radius, is not been widely utilized in construction of nonconventional luminophores despite of its potential competitiveness in nonaromatic photoluminescent polymers. Herein, the “click” type Michael polyaddition is utilized to construct sulfur‐bearing nonconventional luminophores, and two sulfur enriched nonaromatic poly(thioether sulfone)s (PES) are obtained, which demonstrate fluorescence‐phosphorescence dual emission. More investigations concerning the monomer of bis(vinylsulfonyl)methane are further proceeded to support acquired results. Finally, the application of explosive detection by the prepared PES is also conducted.
Toward Olefin Multiblock Copolymers with Tailored Properties: A Molecular Perspective
Authors: Mohammadi Yousef , Saeb Mohammad Reza , Penlidis Alexander , Jabbari Esmaiel , Stadler Florian J. , Zinck Philippe , Vivaldo‐Lima Eduardo 
Published: April 2021

AbstractRecent progress in macromolecular reaction engineering has enabled the synthesis of sequence‐controlled polymers. The advent of olefin block copolymers (OBCs) via chain shuttling polymerization of ethylene with α‐olefins has opened new horizons for the synthesis of polyolefins having a dual character of thermoplastics and elastomers. Nevertheless, the use of two catalysts with different comonomer selectivities and a chain shuttling agent, dragging and dropping live chains between active catalyst centers, made precise tailoring of OBCs microstructure containing hard and soft units a feasible challenge. This work discusses the possibility of predicting properties of OBCs from its simulated molecular patterns. The microstructural characteristics of OBCs are discussed in terms of topology‐related and property‐related features. An intelligent tool, which combines the benefits of kinetic Monte Carlo simulation and artificial neural network modeling, is used to explore the connection between polymerization recipe (catalyst composition, ethylene to 1‐octene monomer ratio, and chain shuttling agent level) and topology‐related as well as property‐related microstructural features. The properties of target OBCs are reflected in the hard block percent, the number of 1‐octene units in the copolymer chains, and the longest ethylene sequence length of the hard and soft segments.
Cluster based nonuniform transformation field analysis: An efficient homogenization for inelastic heterogeneous materials
Authors: Ri Jun‐Hyok , Hong Hyon‐Sik , Ri Sung‐Gyu 
Published: April 2021

AbstractIn this article, the authors propose an efficient numerical homogenization method, the so‐called cluster based nonuniform transformation field analysis (NTFA), for inelastic heterogeneous material. The method enables to predict the effective properties directly from the local constitutive relations for microstructural phases of heterogeneous material, thus no requiring preliminary assumptions and any derivations for the effective constitutive relation as in the conventional NTFA. Evolution of plastic strain field is expressed by combination of nonuniform plastic strain modes evaluated from the nonlinear finite element analysis for training directions previously given and snapshot proper orthogonal decomposition. Eventually, microscopic stress and strain field are represented by scalar reduced variables and plastic strain modes. A simple maximization of minimum distance is proposed in order to choose uniformly distributed training directions on a unit sphere in the load space. Also, scalar reduced variables are directly determined from the integration of local constitutive relation, where material points are compressed into a number of clusters by clustering scheme. Thus, evolution of reduced variables is evaluated by the integration of local constitutive relation only in clusters. Numerical examples that consider material models followedJ2plasticity and pressure‐dependent non‐associated flow rule show that the current approach may predict the effective properties of inelastic heterogeneous material accurately and efficiently. It should be noted that the current approach can be available for material followed not only associated flow rule but also non‐associated flow one.
Unexpected decline in pediatric asthma morbidity during the coronavirus pandemic
Authors: Ulrich Lisa , Macias Charlie , George Ashish , Bai Shasha , Allen Elizabeth 
Published: April 2021

AbstractThe Coronavirus disease 2019 (COVID‐19) pandemic profoundly impacted health care utilization. We evaluated asthma‐related emergency department (ED) and inpatient health care utilization by a county‐specific Medicaid population, ages 2–18, during the COVID‐19 pandemic and compared it to utilization from a 3‐year average including 2017–2019. All‐cause ED utilization and asthma medication fill rates were evaluated during the same timeframes. Relative to the 2017–2019 3‐year average, cumulative asthma‐related ED visits from January through June decreased by 45.8% (p = .03) and inpatient admission rates decreased by 50.5% (p = .03). The decline in asthma‐related ED utilization was greater than the reduction of overall ED use during the same time period, suggesting that the decline involved factors specific to asthma and was not due solely to avoidance of health care facilities. Fill rates for asthma controller medications decreased during this time (p = .03) and quick relief medication fill rates had no significant change (p = .31). Multiple factors may have contributed to the decrease in acute asthma health care visits. Locally, decreased air pollution and viral exposures coincided with the “Stay‐at‐home” order in Ohio, and increased utilization of telehealth for assessment during exacerbations may have impacted outcomes. Identification of the cause of the decline in visit rates could spur new interventions to limit the need for ED and inpatient visits for asthma patients, leading to both economic and health‐associated benefits.
An adaptive finite‐time stable control law for manipulator robots with unknown parameters
Authors: Boutalbi Oussama , Benmahammed Khier , Boukezata Boualem 
Published: April 2021

AbstractThis article develops an adaptive finite‐time stable control algorithm for an accurate manipulation of robot arms considering unknown model parameters and external disturbances. First, a state‐dependent twisting control algorithm is developed for the robust manipulation of robot arms under the consideration of bounded unknown uncertainties conditions. The more challenging problem of robust control design under consideration of totally unknown dynamical parameters is investigated in a second stage by supporting the control law with a suitable online parameters estimator. The objective of the parameters estimator is to drive the vector of estimated parameters to some level that ensures the establishment of real second‐order sliding mode without overloading the discontinuous controller gains. This approach based on combining both techniques of robust and adaptive algorithms allows overcoming large levels of uncertainties while preserving a high level of tracking accuracy without exciting the unwanted phenomena of chattering. The system finite‐time stability is proven by using Lyapunov theory and the weighted homogeneity principle. Practical tests are reported to support theoretical study results.
Reading Anxiety, Engagement, and Achievement: A Comparison of Emergent Bilinguals and English Monolinguals in the Elementary Grades
Authors: Taboada Barber Ana , Klauda Susan Lutz , Wang Weimeng 
Published: April 2021

AbstractSocioemotional constructs have been receiving increased attention as contributors to individuals’ literacy development. However, in comparison with positive socioemotional constructs, negative socioemotional constructs have been understudied with respect to their role in reading achievement in both emergent bilinguals (EBs) and English monolinguals (EMs). In the present study, we addressed this gap by examining reading anxiety in 339 EBs, who primarily spoke Spanish as their first language, and 178 EMs in grades 3–5, using a latent variable approach. We used structural equation modeling to form latent variables for reading anxiety, reading engagement, and reading achievement; compare latent variable means for EBs and EMs; and examine relations among the three focal constructs across the two language groups. The EBs and EMs showed similar levels of reading engagement, whereas the EBs showed a trend toward greater reading anxiety and statistically significantly lower reading achievement. Further, for both EBs and EMs, reading anxiety related negatively to reading achievement, both directly and indirectly through reading engagement, controlling for grade level. However, both the direct and indirect effects were greater for EBs than EMs. We interpret these results in the context of theoretical views of potential mechanisms linking reading anxiety and achievement, giving attention especially to the multidimensional nature of reading engagement. Based on the current findings and those of other research, we conclude by contending that reading anxiety merits increased scrutiny by researchers and educators endeavoring to understand and strengthen students’ reading achievement and socioemotional development during the elementary school years.
Throttle: An efficient approach to mitigate distributed denial of service attacks on software‐defined networks
Authors: Olakanmi Oladayo Olufemi , Odeyemi Kehinde Oluwasesan 
Published: April 2021

AbstractRecently, different approaches such as statistical methods, genetic algorithm, hidden Markov, fuzzy logic, and blockchain have been adopted to detect and prevent distributed denial of services (DDoS) on software‐defined networks. However, most of these methods are not only complex but are also not adaptive, therefore adversaries with high computational resources can successfully launch DDoS attacks. In this work, we propose a security scheme capable of detecting DDoS attacks and throttling down traffics coming from the suspected hosts irrespective of their computational power. To achieve this, we develop three essential models for the scheme for predicting the volume of traffics from different hosts, determining the processing load of the network, and throttling down traffics from the suspicious hosts. We also develop a time tracking digital signature for determining the traffic pattern and sources of traffics. The simulation results show that the scheme is adaptive, efficient, and capable of detecting identity theft and resource exhaustion‐based DDoS attacks without denying services to a legitimate host.
Cyclic behavior of beams rehabilitated by reinforced concrete layers
Authors: Aykaç Sabahattin , Özbek Eray , Tankut Ali Tugrul 
Published: April 2021

AbstractOne of the well‐known methods for rehabilitation of insufficient or damaged reinforced concrete (RC) beams is to add a new RC layer. Although RC beams strengthened or repaired in this way have proved themselves under monotonic and repeated loads, the behavior under cyclic loads has not been adequately investigated yet. In this experimental research, beams were strengthened, repaired, or revived (repaired after heavy damage) using familiar RC layer adding methods and tested under reversal cyclic loading. Ten half‐scaled specimens, composed of columns and a beam, were prepared and 18 tests were conducted on these specimens. The obtained results showed that the strengthened and repaired beams mostly could achieve the monolithic behavior. However, sufficient ductility could not be maintained for the revived ones.