bluuebunny/crossref_metadata_2025 huggingface dataset:
BOLZANO’S MATHEMATICAL INFINITE
Authors: BELLOMO ANNA , MASSAS GUILLAUME
Published: February 2021

Bernard Bolzano (1781–1848) is commonly thought to have attempted to develop a theory of size for infinite collections that follows the so-called part–whole principle, according to which the whole is always greater than any of its proper parts. In this paper, we develop a novel interpretation of Bolzano’s mature theory of the infinite and show that, contrary to mainstream interpretations, it is best understood as a theory of infinite sums. Our formal results show that Bolzano’s infinite sums can be equipped with the rich and original structure of a non-commutative ordered ring, and that Bolzano’s views on the mathematical infinite are, after all, consistent.
Where is the class bias attenuation? The consequences of adopting compulsory voting in Austria-Hungary in 1907
Authors: Kouba Karel
Published: February 2021

Adopting compulsory voting (CV) legislation is expected to produce near-universal turnout, which in turn is assumed to iron out class-based differences in political influence and representation. The article traces the historical process generating the sequential adoption of CV in 8 of the 17 Cisleithanian crownlands of the Austro-Hungarian empire in 1907 and 1911, and leverages a difference-in-differences (DiD) method to estimate its causal effect on turnout and voting patterns in elections to the Imperial Council. Exploiting unique data on the turnout of citizens based on their occupational categories, it further examines whether the adoption of CV attenuated class bias in turnout. Despite a large boost to turnout, CV neither increased support for parties representing the working classes, nor attenuated the class bias in turnout.
Psychometric Properties of the German Short Version of the Maslach	Burnout Inventory – Student Survey
Authors: Turhan Derya , Scheunemann Anne , Schnettler Theresa , Bäulke Lisa , Thies Daniel O. , Dresel Markus , Fries Stefan , Leutner Detlev , Wirth Joachim , Grunschel Carola
Published: February 2021

Abstract. Background: Higher education is a challenging context in which students – particularly those endowed with a small array of resources – are susceptible to suffer from burnout. To screen, identify, and support students that are at risk of burnout, psychometrically robust instruments are essential. To this end, we extended the validation of the German short version of the Maslach Burnout Inventory – Student Survey (MBI-SS-KV) that allows measuring burnout among German-speaking university students. Method: We conducted a longitudinal study and analyzed the factorial validity, reliability, measurement invariance, and convergent as well as discriminant validity of the MBI-SS-KV in a sample of German university students ( N = 1,435). Results: Our results replicated the original three-factor structure of the MBI-SS-KV. Yet, a bi-factor structure of the MBI-SS-KV – composed of a general factor (i.e., student burnout) and three domain-specific factors (i.e., emotional exhaustion, cynicism, and reduced professional efficacy) – revealed a comparable fit and was used for further analyses due to theoretical and methodological advantages. Based on the bi-factor structure of the MBI-SS-KV, nested models with increasing invariance constraints provided support for measurement invariance of this instrument across female and male university students and across time. Besides, the average variance extracted estimates and the comparisons of these estimates with shared variances demonstrated convergent and discriminant validity of the factors emotional exhaustion and cynicism, but not for the factor reduced professional efficacy. Conclusion: To sum up, we found that the MBI-SS-KV is a reliable and for the most part valid instrument for the assessment of student burnout in German higher education.
The Relationship Between Physical Activity, Health, and	Well-Being
Authors: Klussman Kristine , Langer Julia , Nichols Austin Lee
Published: February 2021

Abstract. Background: Most people are comfortable asserting the beneficial effects of physical exercise on mental health and well-being. However, little research has examined how different types of physical activity affect these outcomes. Aims: The current study sought to provide a comprehensive understanding of the differential relationships between different types of physical activity and various aspects of health and well-being. In addition, we sought to understand the role of self-connection in these relationships. Method: One hundred forty-three participants completed a questionnaire designed to measure their current weekly activity as well as their current health and well-being. Specifically, we examined three intensities of activity (walking, moderate, and vigorous) and three types of activity (team-based, community-based, and not team nor community-based) on self-reported health, anxiety, depression, affect, flourishing, job satisfaction, life satisfaction, and meaning in life. In addition, we examined self-connection as a possible moderator of these relationships. Results: Results suggested that physical activity was inconsistently related to health and well-being, and activity intensity and type were important to understanding these relationships. In contrast, self-connection reliably related to health and well-being and moderated the relationship between activity type and the presence of meaning. Limitations: The cross-sectional, self-report nature of the study limits its contribution. In addition, we only examined a subset of all physical activities that people engage in. Conclusion: In all, results suggest that the relationships between physical activity, mental health, and well-being are tenuous, at best. Future research needs to examine these relationships further and continue to examine self-connection to determine how to best increase health and well-being through physical activity.
Study of the Quasi 10‐Day Waves in the MLT Region During the 2018 February SSW by a Meteor Radar Chain
Authors: Luo Jiahui , Gong Yun , Ma Zheng , Zhang Shaodong , Zhou Qihou , Huang Chunming , Huang Kaiming , Yu You , Li Guozhu
Published: February 2021

We present a study of the quasi 10‐day waves (Q10DWs) in the mesosphere and lower thermosphere (MLT) during a sudden stratospheric warming (SSW) event in February 2018 based on three meteor radars located at Mohe (MH, 53.5°N, 122.3°E), Beijing (BJ, 40.3°N, 116.2°E), and Wuhan (WH, 30.5°N, 116.6°E). The enhanced Q10DWs are observed in the meridional component at MH and in the zonal component at BJ and WH. In the meridional component, the monthly mean Q10DW amplitudes in February 2018 are greater than 10 m/s at MH but weaker than ∼7 m/s at BJ and WH. In the zonal component, monthly mean Q10DWs amplitudes are ∼15 m/s at BJ and WH but only 9 m/s at MH. These latitudinal differences of the Q10DWs in the MLT region are very likely due to the Q10DW activity in the lower atmosphere and the mean background winds. The strong southward winds might bring the wave energy to MH in the meridional component during the occurrence of SSW, while the enhanced Q10DWs in the zonal component at BJ and WH are likely associated with the strong Q10DWs in the lower atmosphere and weakening eastward winds after the central date of the SSW. The significance test indicates that the enhanced Q10DWs in the meridional wind of MH and in the zonal wind of WH are very likely affected by the SSW. In addition, nonlinear interactions between the Q10DWs and other planetary waves also modulate the variations in the MLT region at BJ during the SSW.
Validation of ICON‐MIGHTI Thermospheric Wind Observations: 2. Green‐Line Comparisons to Specular Meteor Radars
Authors: Harding Brian J. , Chau Jorge L. , He Maosheng , Englert Christoph R. , Harlander John M. , Marr Kenneth D. , Makela Jonathan J. , Clahsen Matthias , Li Guozhu , Ratnam M. Venkat , Bhaskar Rao S. Vijaya , Wu Yen‐Jung J. , England Scott L. , Immel Thomas J.
Published: February 2021

We compare coincident thermospheric neutral wind observations made by the Michelson Interferometer for Global High‐Resolution Thermospheric Imaging (MIGHTI) on the Ionospheric Connection Explorer (ICON) spacecraft, and four ground‐based specular meteor radars (SMRs). Using the green‐line MIGHTI channel, we analyze 1158 coincidences between Dec 2019 and May 2020 in the altitude range from 94 to 104 km where the observations overlap. We find that the two datasets are strongly correlated (r = 0.82) with a small mean difference (4.5 m/s). Although this agreement is good, an analysis of known error sources (e.g., shot noise, calibration errors, and analysis assumptions) can only account for about a quarter of the disagreement variance. The unexplained variance is 27.8% of the total signal variance and could be caused by unknown errors. However, based on an analysis of the spatial and temporal averaging of the two measurement modalities, we suggest that some of the disagreement is likely caused by temporal variability of the wind on scales ≲70 min. The observed magnitudes agree well during the night, but during the day, MIGHTI observes 16%–25% faster winds than the SMRs. This remains unresolved but is similar in certain ways to previous SMR‐satellite comparisons.
Editorial Expression of Concern: Tumor necrosis factor-inducible gene 6 protein ameliorates chronic liver damage by promoting autophagy formation in mice
Authors: Wang Sihyung , Lee Chanbin , Kim Jieun , Hyun Jeongeun , Lim Minso , Cha Hyuk-Jin , Oh Seh-Hoon , Choi Yung Hyun , Jung Youngmi
Published: February 2021

An Editorial Expression of Concern to this paper has been published: https://doi.org/10.1038/s12276-021-00554-6
Health-based evaluation of ambient air measurements of PM2.5 and volatile organic compounds near a Marcellus Shale unconventional natural gas well pad site and a school campus
Authors: Long Christopher M. , Briggs Nicole L. , Cochran Brian A. , Mims Destiny M.
Published: February 2021

Background

Limited air monitoring studies with long-term measurements during all phases of development and production of natural gas and natural gas liquids have been conducted in close proximity to unconventional natural gas well pads.

Objective

Conducted in an area of Washington County, Pennsylvania, with extensive Marcellus Shale development, this study investigated whether operations at an unconventional natural gas well pad may contribute to ambient air concentrations of potential health concern at a nearby school campus.

Methods

Almost 2 years of air monitoring for fine particulate matter (PM2.5) and volatile organic compounds (VOCs) was performed at three locations between 1000 and 2800 feet from the study well pad from December 2016 to October 2018. PM2.5 was measured continuously at one of the three sites using a beta attenuation monitor, while 24-h stainless steel canister samples were collected every 6 days at all sites for analysis of 58 VOCs.

Results

Mean PM2.5 concentrations measured during the different well activity periods ranged from 5.4 to 9.5 μg/m3, with similar levels and temporal changes as PM2.5 concentrations measured at a regional background location. The majority of VOCs were either detected infrequently or not at all, with measurements for a limited number of VOCs indicating the well pad to be a source of small and transient contributions.

Significance

All measurement data of PM2.5 and 58 VOCs, which reflect the cumulative contributions of emissions from the study well pad and other local/regional air pollutant sources (e.g., other well pads), were below health-based air comparison values, and thus do not provide evidence of either 24-hour or long-term air quality impacts of potential health concern at the school.
Climate change alters temporal dynamics of alpine soil microbial functioning and biogeochemical cycling via earlier snowmelt
Authors: Broadbent Arthur A D , Snell Helen S K , Michas Antonios , Pritchard William J , Newbold Lindsay , Cordero Irene , Goodall Tim , Schallhart Nikolaus , Kaufmann Ruediger , Griffiths Robert I , Schloter Michael , Bahn Michael , Bardgett Richard D
Published: February 2021

Soil microbial communities regulate global biogeochemical cycles and respond rapidly to changing environmental conditions. However, understanding how soil microbial communities respond to climate change, and how this influences biogeochemical cycles, remains a major challenge. This is especially pertinent in alpine regions where climate change is taking place at double the rate of the global average, with large reductions in snow cover and earlier spring snowmelt expected as a consequence. Here, we show that spring snowmelt triggers an abrupt transition in the composition of soil microbial communities of alpine grassland that is closely linked to shifts in soil microbial functioning and biogeochemical pools and fluxes. Further, by experimentally manipulating snow cover we show that this abrupt seasonal transition in wide-ranging microbial and biogeochemical soil properties is advanced by earlier snowmelt. Preceding winter conditions did not change the processes that take place during snowmelt. Our findings emphasise the importance of seasonal dynamics for soil microbial communities and the biogeochemical cycles that they regulate. Moreover, our findings suggest that earlier spring snowmelt due to climate change will have far reaching consequences for microbial communities and nutrient cycling in these globally widespread alpine ecosystems.
Sequence modification in copoly(ester-imide)s: a catalytic/supramolecular approach to the evolution and reading of copolymer sequence information
Authors: Knappert Marcus , Colquhoun Howard M.
Published: February 2021

Catalytic ester-interchange reactions, analogous to mutation and recombination, allow new sequence information to be written statistically into poly(ester-imide) chains based on NDI (1,4,5,8-naphthalenetetracarboxylic diimide) units. Thus, both the insertion of the cyclic ester cyclopentadecanolide (“exaltolide”) into an NDI-based homopolymer and quantitative sequence exchange between two different homopoly(ester-imide)s are catalyzed by di-n-butyl tin(IV) oxide. Emerging sequences are identified at the triplet and quintet levels using supramolecular complexation of pyrene-d10 at the NDI residues to amplify the separation of 1H NMR resonances associated with different sequences. In such systems, pyrene is able to act as a “reader molecule” by generating different levels of ring-current shielding from the different patterns of supramolecular binding to all NDI-centered sequences of a given length.
A meet-up of two second messengers: the c-di-AMP receptor DarB controls (p)ppGpp synthesis in Bacillus subtilis
Authors: Krüger Larissa , Herzberg Christina , Wicke Dennis , Bähre Heike , Heidemann Jana L. , Dickmanns Achim , Schmitt Kerstin , Ficner Ralf , Stülke Jörg
Published: February 2021

Many bacteria use cyclic di-AMP as a second messenger to control potassium and osmotic homeostasis. In Bacillus subtilis, several c-di-AMP binding proteins and RNA molecules have been identified. Most of these targets play a role in controlling potassium uptake and export. In addition, c-di-AMP binds to two conserved target proteins of unknown function, DarA and DarB, that exclusively consist of the c-di-AMP binding domain. Here, we investigate the function of the c-di-AMP-binding protein DarB in B. subtilis, which consists of two cystathionine-beta synthase (CBS) domains. We use an unbiased search for DarB interaction partners and identify the (p)ppGpp synthetase/hydrolase Rel as a major interaction partner of DarB. (p)ppGpp is another second messenger that is formed upon amino acid starvation and under other stress conditions to stop translation and active metabolism. The interaction between DarB and Rel only takes place if the bacteria grow at very low potassium concentrations and intracellular levels of c-di-AMP are low. We show that c-di-AMP inhibits the binding of DarB to Rel and the DarB–Rel interaction results in the Rel-dependent accumulation of pppGpp. These results link potassium and c-di-AMP signaling to the stringent response and thus to the global control of cellular physiology.
Near-surface softening and healing in eastern Honshu associated with the 2011 magnitude-9 Tohoku-Oki Earthquake
Authors: Wang Su-Yang , Zhuang Hai-Yang , Zhang Hao , He Hong-Jun , Jiang Wei-Ping , Yao Er-Lei , Ruan Bin , Wu Yong-Xin , Miao Yu
Published: February 2021

The near-surface part of the crust, also called the skin of the earth, is the arena of human activity of which the stiffness is of great concern to engineers in infrastructure construction. The stiffness reduction of near-surface geomaterials also plays a vital role in geohazards triggering. However, the physical mechanism behind the material softening is still not fully understood. Here, we report a coseismic shear-wave velocity reduction in the near surface by up to a few tens of percent during the strongest shaking from the 11 March 2011 Tohoku-Oki Earthquake and a subsequent two-stage healing process including a rapid recovery within a few minutes and a slow recovery over many years. We also present a theoretical contact model between mineral grains in geomaterials containing multiple metastable contacts at small separations due to the oscillatory hydration interaction, which can explain the emergence of different stages in the healing process.
Interfacial engineering of Bi2S3/Ti3C2Tx MXene based on work function for rapid photo-excited bacteria-killing
Authors: Li Jianfang , Li Zhaoyang , Liu Xiangmei , Li Changyi , Zheng Yufeng , Yeung Kelvin Wai Kwok , Cui Zhenduo , Liang Yanqin , Zhu Shengli , Hu Wenbin , Qi Yajun , Zhang Tianjin , Wang Xianbao , Wu Shuilin
Published: February 2021

In view of increasing drug resistance, ecofriendly photoelectrical materials are promising alternatives to antibiotics. Here we design an interfacial Schottky junction of Bi2S3/Ti3C2Tx resulting from the contact potential difference between Ti3C2Tx and Bi2S3. The different work functions induce the formation of a local electrophilic/nucleophilic region. The self-driven charge transfer across the interface increases the local electron density on Ti3C2Tx. The formed Schottky barrier inhibits the backflow of electrons and boosts the charge transfer and separation. The photocatalytic activity of Bi2S3/Ti3C2Tx intensively improved the amount of reactive oxygen species under 808 nm near-infrared radiation. They kill 99.86% of Staphylococcus aureus and 99.92% of Escherichia coli with the assistance of hyperthermia within 10 min. We propose the theory of interfacial engineering based on work function and accordingly design the ecofriendly photoresponsive Schottky junction using two kinds of components with different work functions to effectively eradicate bacterial infection.
Dysregulation of REV-ERBα impairs GABAergic function and promotes epileptic seizures in preclinical models
Authors: Zhang Tianpeng , Yu Fangjun , Xu Haiman , Chen Min , Chen Xun , Guo Lianxia , Zhou Cui , Xu Yuting , Wang Fei , Yu Jiandong , Wu Baojian
Published: February 2021

To design potentially more effective therapies, we need to further understand the mechanisms underlying epilepsy. Here, we uncover the role of Rev-erbα in circadian regulation of epileptic seizures. We first show up-regulation of REV-ERBα/Rev-erbα in brain tissues from patients with epilepsy and a mouse model. Ablation or pharmacological modulation of Rev-erbα in mice decreases the susceptibility to acute and chronic seizures, and abolishes diurnal rhythmicity in seizure severity, whereas activation of Rev-erbα increases the animal susceptibility. Rev-erbα ablation or antagonism also leads to prolonged spontaneous inhibitory postsynaptic currents and elevated frequency in the mouse hippocampus, indicating enhanced GABAergic signaling. We also identify the transporters Slc6a1 and Slc6a11 as regulators of Rev-erbα-mediated clearance of GABA. Mechanistically, Rev-erbα promotes the expressions of Slc6a1 and Slc6a11 through transcriptional repression of E4bp4. Our findings propose Rev-erbα as a regulator of synaptic function at the crosstalk between pathways regulating the circadian clock and epilepsy.
Quantification of Actaea racemosa L. (black cohosh) from some of its potential adulterants using qPCR and dPCR methods
Authors: Shanmughanandhan Jeevitha , Shanmughanandhan Dhivya , Ragupathy Subramanyam , Henry Thomas A. , Newmaster Steven G.
Published: February 2021

The demand for popular natural health products (NHPs) such as Black Cohosh is increasing considerably, which in turn challenges quality assurance (QA) throughout the supply chain. To detect and quantify the target species present in a given NHP, DNA-based molecular techniques such as Real-time quantitative PCR (qPCR) and digital PCR (dPCR) are standard tools in the food and pathogen testing industries. There is a gap in the literature concerning validated quantitative PCR methods for botanicals that can be utilized for QA and good manufacturing practices. The objective of this study is to develop an efficient quantification method using qPCR and dPCR techniques for the detection and quantification of Actaea racemosa (Black cohosh) NHPs from its potential adulterants. These developed methods are validated for applicability on commercial NHPs. Species-specific hydrolysis probe assays were designed to analyze the black cohosh NHPs using qPCR and dPCR techniques. The results confirmed that the developed qPCR and dPCR methods are highly precise for identifying and quantifying black cohosh NHPs, indicating their potential applicability in future routine industrial and laboratory testing. This enables a single qPCR test to determine not only the presence of a specific botanical, but also the amount when mixed with an adulterant.
Predictive values of multiple non-invasive markers for myocardial fibrosis in hypertrophic cardiomyopathy patients with preserved ejection fraction
Authors: Li Yumin , Liu Jia , Cao Yukun , Han Xiaoyu , Shao Guozhu , Zhou Xiaoyue , Gu Jin , Liu Tong , Cui Yue , Shi Heshui
Published: February 2021

Myocardial fibrosis assessed by late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) is associated with cardiovascular outcomes in hypertrophic cardiomyopathy (HCM) patients, but little is known about the utility of non-invasive markers for detecting LGE. This study aims to explore the association between cardiac-specific biomarkers, CMR myocardial strain, left ventricular (LV) hypertrophy and LGE in HCM patients with preserved ejection fraction (EF) and investigate the predictive values of these indexes for LGE. We recruited 33 healthy volunteers and 86 HCM patients with preserved EF to undergo contrast-enhanced CMR examinations. In total, 48 of 86 HCM patients had the presence of LGE. The LGE-positive patients had significant higher serum high-sensitivity cardiac troponin I (hs-cTnI) and N-terminal pro b-type natriuretic peptide (Nt-proBNP) levels and lower global longitudinal (GLS) and circumferential (GCS) strains than the LGE-negative group. The LGE% was independently associated with the Nt-proBNP levels, GCS, LV end-diastolic maximum wall thickness (MWT) and beta-blocker treatment. In the receiver operating characteristic curve analysis, the combined parameters of Nt-proBNP ≥ 108.00 pg/mL and MWT ≥ 17.30 mm had good diagnostic performance for LGE, with a specificity of 81.25% and sensitivity of 70.00%. These data indicate that serum Nt-proBNP is a potential biomarker associated with LGE% and, combined with MWT, were useful for identifying myocardial fibrosis in HCM patients with preserved EF. Additionally, LV GCS may be a more sensitive indicator for reflecting the presence of myocardial fibrosis than GLS.
In situ electron microscopy study of structural transformations in 2D CoSe2
Authors: Gavhane Dnyaneshwar S. , van Gog Heleen , Thombare Balu , Lole Gaurav , Christiaan Post L. , More Mahendra A. , van Huis Marijn A.
Published: February 2021

Thermally induced structural transformation of 2D materials opens unique avenues for generating other 2D materials by physical methods. Imaging these transitions in real time provides insight into synthesis routes and property tuning. We have used in situ transmission electron microscopy (TEM) to follow thermally induced structural transformations in layered CoSe2. Three transformation processes are observed: orthorhombic to cubic-CoSe2, cubic-CoSe2 to hexagonal-CoSe, and hexagonal to tetragonal-CoSe. In particular, the unit-cell-thick orthorhombic structure of CoSe2 transforms into cubic-CoSe2 via rearrangement of lattice atoms. Cubic-CoSe2 transforms to hexagonal-CoSe at elevated temperatures through the removal of chalcogen atoms. All nanosheets transform to basal-plane-oriented hexagonal 2D CoSe. Finally, the hexagonal to tetragonal transformation in CoSe is a rapid process wherein the layered morphology of hexagonal-CoSe is broken and islands of tetragonal-CoSe are formed. Our results provide nanoscopic insights into the transformation processes of 2D CoSe2 which can be used to generate these intriguing 2D materials and to tune their properties by modifying their structures for electro-catalytic and electronic applications.
A flexible hybrid capacitor based an NiCo2S4 nanowire electrode with an ultrahigh capacitance
Authors: Xia Tong , Liu Ying , Dai Meizhen , Xia Qing , Wu Xiang
Published: February 2021

In this study, we synthesized NiCo2S4 nanowire bundles on a nickel foam via facile hydrothermal routes. The assembled asymmetric supercapacitor exhibits excellent mechanical stability even at different bending angles.
A mechanistic study of electrode materials for rechargeable batteries beyond lithium ions byin situtransmission electron microscopy
Authors: Yousaf Muhammad , Naseer Ufra , Li Yiju , Ali Zeeshan , Mahmood Nasir , Wang Lei , Gao Peng , Guo Shaojun
Published: February 2021

This article summarizes the real-time information on electrodes, electrolytes and their interfaces of various rechargeable battery systems including heavier alkali ion, lithium-sulfur, alkali-metal oxygen and all-solid-state batteries made byin situtransmission electron microscopy.
Chlorine doping of MoSe2 flakes by ion implantation
Authors: Prucnal Slawomir , Hashemi Arsalan , Ghorbani-Asl Mahdi , Hübner René , Duan Juanmei , Wei Yidan , Sharma Divanshu , Zahn Dietrich R. T. , Ziegenrücker René , Kentsch Ulrich , Krasheninnikov Arkady V. , Helm Manfred , Zhou Shengqiang
Published: February 2021

Controlled doping of MoSe2 realized by low-energy ion implantation and millisecond-range intense pulse light annealing.
Stabilization effects in binary colloidal Cu and Ag nanoparticle electrodes under electrochemical CO2 reduction conditions
Authors: Wu Longfei , Kolmeijer Kees E. , Zhang Yue , An Hongyu , Arnouts Sven , Bals Sara , Altantzis Thomas , Hofmann Jan P. , Costa Figueiredo Marta , Hensen Emiel J. M. , Weckhuysen Bert M. , van der Stam Ward
Published: February 2021

Colloidal Cu and Ag nanoparticles retain their shape during the CO2 reduction reaction (−0.8 V vs. RHE) due to immiscibility of the lattices and synergy at the nanoscale results in enhanced methane and C2 product formation.
Tandem [4 + 2]/[2 + 2] cycloaddition of o-carboryne with enynes: facile construction of carborane-fused tricyclics
Authors: Zhang Jie , Xie Zuowei
Published: February 2021

An unprecedented tandem [4 + 2]/[2 + 2] cycloaddition of o-carboryne with enynes has been disclosed for the efficient synthesis of various carborane-fused tricyclics, in which a reactive carborane-fused 1,2-cyclohexadiene intermediate is involved.
Sustainable gas conversion by gliding arc plasmas: a new modelling approach for reactor design improvement
Authors: Van Alphen Senne , Jardali Fatme , Creel James , Trenchev Georgi , Snyders Rony , Bogaerts Annemie
Published: February 2021

We present a new modelling approach for the design and development of gliding arc plasma reactors, revealing the fluid dynamics, the arc behaviour and the plasma chemistry by solving a unique combination of five complementary models.
Correction: Fragment-based covalent ligand discovery
Authors: Lu Wenchao , Kostic Milka , Zhang Tinghu , Che Jianwei , Patricelli Matthew P. , Jones Lyn H. , Chouchani Edward T. , Gray Nathanael S.
Published: February 2021

Correction for ‘Fragment-based covalent ligand discovery’ by Wenchao Lu et al., RSC Chem. Biol., 2021, DOI: 10.1039/d0cb00222d.
A review on the stability of inorganic metal halide perovskites: challenges and opportunities for stable solar cells
Authors: Xiang Wanchun , Liu Shengzhong (Frank) , Tress Wolfgang
Published: February 2021

The composition, light, moisture and oxygen all affect the stability of metal halide inorganic perovskites, whose degradation mechanisms are significantly different from those of hybrid perovskites.
Mn2+ activated Ca-α-SiAlON – broadband deep-red luminescence and sensitization by Eu2+, Yb2+ and Ce3+
Authors: Sontakke Atul D. , van Bunningen Arnoldus J. , Wakui Sadakazu , Meijerink Andries
Published: February 2021

Mn2+ occupies [Ca(N,O)7] polyhedral site in Ca-α-SiAlON. The polyhedral site imposes stronger crystal field and nephelauxetic shift on Mn2+ 4T1 → 6A1 transition, leading to an intense and broad deep-red emission.
Anion ordering and vacancy defects in niobium perovskite oxynitrides
Authors: Brown Joshua J. , Shao Youxiang , Ke Zhuofeng , Page Alister J.
Published: February 2021

First-principles calculations predict the stability and mobility of vacancy defects in niobium perovskite oxynitrides, aiding defect engineering for enhanced photocatalysis.
Protecting-group-free synthesis of thiol-functionalized degradable polyesters
Authors: Liu Yihuan , Yin Fan , Hu Xin , Zhu Ning , Guo Kai
Published: February 2021

Protecting-group-free synthesis of thiol-functionalized degradable polyesters has been developed by using chemoselective catalysis and microflow technology.
The contribution of intermolecular forces to phototropic actuation of liquid crystalline elastomers
Authors: Hebner Tayler S. , Bowman Christopher N. , White Timothy J.
Published: February 2021

Azobenzene-functionalized crystalline elastomers containing a monomer with reduced aromatic content exhibits enhanced phototropic response.
The molecular basis of plant cellulose synthase complex organisation and assembly
Authors: Wilson Thomas H , Kumar Manoj , Turner Simon R
Published: February 2021

The material properties of cellulose are heavily influenced by the organisation of β-1,4-glucan chains into a microfibril. It is likely that the structure of this microfibril is determined by the spatial arrangement of catalytic cellulose synthase (CESA) proteins within the cellulose synthase complex (CSC). In land plants, CESA proteins form a large complex composed of a hexamer of trimeric lobes termed the rosette. Each rosette synthesises a single microfibril likely composed of 18 glucan chains. In this review, the biochemical events leading to plant CESA protein assembly into the rosette are explored. The protein interfaces responsible for CESA trimerization are formed by regions that define rosette-forming CESA proteins. As a consequence, these regions are absent from the ancestral bacterial cellulose synthases (BcsAs) that do not form rosettes. CSC assembly occurs within the context of the endomembrane system, however the site of CESA assembly into trimers and rosettes is not determined. Both the N-Terminal Domain and Class Specific Region of CESA proteins are intrinsically disordered and contain all of the identified phosphorylation sites, making both regions candidates as sites for protein–protein interactions and inter–lobe interface formation. We propose a sequential assembly model, whereby CESA proteins form stable trimers shortly after native folding, followed by sequential recruitment of lobes into a rosette, possibly assisted by Golgi-localised STELLO proteins. A comprehensive understanding of CESA assembly into the CSC will enable directed engineering of CESA protein spatial arrangements, allowing changes in cellulose crystal packing that alter its material properties.
An energy efficient data gathering scheme for wireless sensor networks using hybrid crow search algorithm
Authors: Kodoth Praveen Kumar , Edachana Govindaraj
Published: February 2021

The most important challenge in Wireless Sensor Networks (WSNs) is to investigate mechanisms for energy‐efficient data gathering. Within the operating range of Wireless Sensor Network (WSN), the sensor nodes are distributed to send the sensed data to the base station. During the transaction of data, some amount of energy is wasted. So, this work is focused on providing an energy‐efficient data gathering scheme by Circular Clustering and Hybrid Crow Search Algorithm for enhancing the lifetime of network. Learning to maximize the lifetime of network and to attain supreme energy efficiency. In the proposed scheme, for robust data gather node selection; initially, the circular cell clusters are accomplished by separating the entire area of the sensor network. Hereafter, to select precise data gathering node in the circular cell cluster region, a multi objective based weighted sum approach is employed for proximity, communication cost, residual energy and coverage. Further, a routing and dynamic mobile sink relocation mechanism are performed to gather data form cluster head using hybrid crow search algorithm (HCSA). Based on the parameters such as total energy consumption, many alive nodes, and network lifetime, the capability of the proposed technique has been investigated. The proposed strategy has better performance analysis when contrasted to the existing techniques.
Flat winding made of aluminum or copper sheet for axial flux machines
Authors: Cakal Gokhan , Keysan Ozan
Published: February 2021

A novel flat winding topology has been proposed as an alternative to conventional windings with stranded round wires and other bar wound windings. The proposed winding is manufactured from thin conductor sheets by industrial tools such as stamping press, laser cutter, or water jet. As these tools are widely used in the production of electric machines, the flat winding topology can provide ease of manufacturing without significant modification to the production line. Besides, superior current ratings, shortened end windings, and high fill factors are other advantages of flat winding. Its performance is measured by comparison study between flat wired prototype machine and the stranded wired machines with similar ratings presented in the literature. The proposed winding is implemented on an axial flux permanent magnet machine. Analytical modeling is presented, including field modeling, voltage, torque derivations, and loss modeling. Then, experimental verification of a 1.4‐kW and 26‐Nm prototype with copper and aluminum flat windings is presented, and the performances of two are compared.
Torsional vibration analysis of the surface‐mounted permanent magnet synchronous machine using analytical model considering flux harmonics
Authors: Ren Jie , Zhao Wenliang , Wang Xiuhe , Xing Zezhi
Published: February 2021

The torsional vibration of the surface‐mounted permanent magnet synchronous machine (SPMSM) caused by torque ripple is analysed herein. First, an improved mathematic model of the SPMSM accounting for torsional vibration effect is proposed, which is composed of the voltage equation and motion equation. The voltage equation is established in abc coordinate taking flux harmonics into account, whereas the motion equation is derived based on a simplified two‐mass mechanical model. The perfect precision of the established model is verified by the finite element method (FEM) and experimental results. Then, an analytical method for analysing the machine steady‐state and dynamic torsional vibration response is used based on the proposed mathematic model. The torsional vibrations of a 6p/36s SPMSM under several conditions are analysed and compared. It is shown that the resonance caused by the 12‐th‐order torque harmonic may occur during the start‐up process. Furthermore, the operational speed range of the machine can be extended by suitably decreasing the stiffness coefficient.
Optimising protein synthesis in cell‐free systems, a review
Authors: Batista Angelo C. , Soudier Paul , Kushwaha Manish , Faulon Jean‐Loup
Published: February 2021

Over the last decades, cell‐free systems have been extensively used for in vitro protein expression. A vast range of protocols and cellular sources varying from prokaryotes and eukaryotes are now available for cell‐free technology. However, exploiting the maximum capacity of cell free systems is not achieved by using traditional protocols. Here, what are the strategies and choices one can apply to optimise cell‐free protein synthesis have been reviewed. These strategies provide robust and informative improvements regarding transcription, translation and protein folding which can later be used for the establishment of individual best cell‐free reactions per lysate batch.
Design and development of a cascaded modular multi‐level converter based on current‐fed quadruple‐active bridge converters for grid integration of photovoltaic systems
Authors: Malekjamshidi Zahra , Jafari Mohammad
Published: February 2021

This article proposes a new topology of a cascaded modular multi‐level converter (MMC) based on the current‐fed quadruple active bridge (CFQAB) converters for grid integration of photovoltaic (PV) systems. The MMC topology includes multiple cascaded converter modules in each phase of a three‐phase system. Each individual module is further formed by a PV‐linked CFQAB dc–dc converter to integrate the PV outputs and supply it to a high‐voltage dc (HVDC) bus and further to a cascaded inverter to converter to the ac voltage for the distribution grid. The proposed topology features a wide input voltage range, lower current ripple and smaller size due to the use of CFQAB converter as the building block, which makes it an ideal choice for PV applications. The operation principle of the MMC, converter modules and the control techniques have been presented in detail. A scaled‐down prototype of the topology is implemented to validate the operation of the proposed topology and the control systems.
Prediction of transformer fault in cooling system using combining advanced thermal model and thermography
Authors: Shiravand Vahid , Faiz Jawad , Samimi Mohammad Hamed , Mehrabi‐Kermani Mehdi
Published: February 2021

Thermal models are widely used for diagnosing thermal faults, predicting the thermal behaviour, estimating hot spots, and evaluating the loading capacity. This paper uses a new advanced thermal model, thermography method, and computational fluid dynamic separately to obtain the top‐oil and radiator temperatures. The model consists of four thermal points: the ambient, top‐oil, winding, and radiator. The heat transfer phenomena between these points are modelled by nonlinear thermal resistors. Adding the radiator thermal point to the model improves the accuracy. This is shown by comparing the proposed model with the standard and physical thermal models. The proposed thermal model is validated using the experimental results of three distribution transformers. The thermography camera and image processing technique are also employed to take thermal images and analyse them, respectively. By analysing the thermal images with the image processing method, the top‐oil temperature and radiator temperature are obtained. Furthermore, the computational fluid dynamic model is used to analyse and obtain more accurate prediction of the thermal behaviour of the transformer. Finally, it is proposed to detect faults inside the transformer cooling system by comparing the top‐oil and radiator temperature from two methods presented, that is, advanced thermal modelling and thermography with image processing.
Enhanced reinforcement learning assisted dynamic power management model for internet‐of‐things centric wireless sensor network
Authors: Hosahalli Doreswamy , Srinivas Kunal G.
Published: February 2021

The exponential rise in the demands of the wireless communication system has alarmed industries to achieve more efficient and quality‐of‐service (QoS) centric wireless communication networks. The decentralised and infrastructure‐less nature of wireless sensor networks (WSNs) enable it to be one of the most sought and used wireless network globally. Its cost‐efficiency and functional robustness towards low‐power lossy networks make it suitable for internet‐of‐things (IoT) applications. In recent years, IoT technologies have been used in diverse applications, including Smart City Planning and Management (SCPM). Although, mobile‐WSN has played a decisive role in IoT enabled SCPM, its routing optimality and power transmission have always remained challenging. Noticeably, major existing researches address mainly on routing optimisation and very few efforts are made towards dynamic power management (DPM) under non‐linear network conditions. With this motive, in this study, a highly robust and efficient QoS – centric reinforcement learning‐based DPM model has been developed for mobile‐WSN to be used in SCPM. Unlike classical reinforcement learning methods, the authors’ proposed advanced reinforcement learning‐based DPM model exploits both known and unknown network parameters and state‐activity values, including bit‐error probability, channel state information, holding time, buffer cost etc. to perform dynamic switching decision. The key objective of the proposed model is to ensure optimal QoS oriented DPM and adaptive switching control to yield reliable transmission with the maximum possible resource utilisation. To achieve it, they proposed model has been developed as a controlled‐Markov decision problem by applying hidden Markov model it obtains known and unknown parameters, which are subsequently learnt using an enhanced reinforcement learning to yield maximum resource utilisation while maintaining low buffer cost, holding cost and bit‐error probability to retain the QoS provision.
Interest flooding attack mitigation in a vehicular named data network
Authors: Abdullah Muhammad , Raza Imran , Zia Tanveer , Hussain Syed Asad
Published: February 2021

Vehicular named data network (VNDN) is the next‐generation network architecture for intelligent transportation system. Contrary to the conventional transmission control protocol/internet protocol (TCP/IP) communication model, VNDN follows a data‐centric approach where the user is interested in ‘WHAT’ instead of ‘WHERE’. Interest flooding attack (IFA) is one of the prominent security concerns in VNDNs. In IFA, attackers request for non‐existent content to exhaust network resources and cause Interest packet flooding across the network. A novel attack mitigation scheme to counter IFA in VNDN has been proposed in this study. The proposed priority‐based per‐flow Interest rate monitoring (PP‐FIRM) scheme determines the suspicious flow of malicious incoming Interest packets in attacked vehicles. A priority flag is assigned to the incoming flow of Interest packets that detects the occurrence of an attack. The priority of incoming Interest packet flow is calculated using a collaborative or neighbour‐assisted approach. A comparison with another attack mitigation scheme validates that the proposed scheme performs better in terms of an improved cache hit ratio and Interest satisfaction ratio during the attack window. Besides this, pending Interest table utilisation, packet collisions rate, Interest packets retransmission count, end‐to‐end delay, and the ratio of timed out Interest packets have also been reduced. Furthermore, the scalability of the proposed research strategy is also evaluated by changing the density of attackers in real time. Moreover, in the proposed attack mitigation model, the rate of incoming legitimate Interest packets increases by reducing the drop rate of valid Interest packets.
A data‐driven approach to estimate emissions for market‐based power system test cases
Authors: Durvasulu Venkat , Hansen Timothy M.
Published: February 2021

A data‐driven technique to determine greenhouse gas (GHG) and air‐pollutant (AP) emissions from bulk‐power system simulations is proposed. The proposed technique emulates the dispatch of a bulk‐power system using open‐source hourly fuel‐energy data from an actual U.S. electricity market (i.e. PJM). Sixteen different fuel types were analysed from real generator data and dynamically assigned to power system test cases to statistically represent the real fuel‐energy mix. Each test case generator is assigned a heat‐rate function based on open‐source real generator data to estimate realistic emissions from power system test case simulations. These augmented test cases can be used to simulate how changes in load and generation impact power system emissions to determine the environmental sustainability of new technologies (e.g. demand‐side management). The proposed technique is implemented on three different power system test cases, and the simulated emissions are compared with the actual emissions of the PJM system. The results from the test systems are found to accurately emulate the time‐series values of fuel‐mix, emissions, and marginal costs of PJM.
APPLICATION OF TWO STAGE METHOD OF CHARACTERISTICS / SP3 METHODOLOGY TO TRISO-FUELLED LEU SPACE REACTOR IN WIMS 11
Authors: Read Nathaniel , Shwageraus Eugene
Published: February 2021

In order to minimise the mass of a 1MWe LEU space fission power system design, a rapid neutronics analysis tool is sought. A two-stage deterministic analysis routine has been constructed using a core-plane method of characteristics calculation followed by a full-core SP3 calculation, within the ANSWERS© code WIMS11. This is compared to a faster route that skips the core-plane calculation and also the Monte Carlo code Serpent. Results suggest sufficiently good agreement for the WIMS-based methods to be useful in a full system mass-minimising optimisation routine.
APPLICATION OF A CUSTOM DEPLETION FRAMEWORK TO THE PREDICTION OF NEUTRON FLUX DISTRIBUTION THROUGH DEPLETION
Authors: Johnson Andrew , Kotlyar Dan
Published: February 2021

Previous works by the authors have introduced the spatial flux variation method (SFV) for predicting the changes in neutron flux due to a change in material compositions. In order to remove a full transport solution at the end-of-step, this work presents a framework responsible for computing macroscopic cross sections after a depletion event. These end of-step cross sections are estimators of changes in neutron loss and production, and enable the prediction of neutron flux using only information obtained from a single beginning of-step transport solution. The framework reads in all relevant data needed to model the depletion system, including one-group cross sections and effective fission yields to reproduce the problem using an external solver. The framework also supports extrapolating microscopic cross sections in order to rebuild the end-of-step macroscopic cross sections needed for the flux prediction. Results indicate that the SFV method is not adversely effected by the external depletion solution, and can be implemented alongside an existing transport-depletion framework.
ADVANCES IN STUDSVIK’S SYSTEM FOR SPENT FUEL ANALYSES
Authors: Simeonov Teodosi , Wemple Charles
Published: February 2021

Studsvik’s approach to spent nuclear fuel analyses combines isotopic concentrations, fluxes, and cross-sections, calculated by the CASMO5 neutron transport and depletion code, with irradiation history data from the SIMULATE5 reactor core simulator and tabulated isotopic decay data. These data sources are used and processed by the SNF code to compute the spent nuclear fuel characteristics. Recent advances in the system, including cross-sections and decay data from ENDF/B-VIII.R0, are presented in this paper, together with validation results against decay heat power and isotopic compositions measurements. Measurements conducted at the Swedish interim storage facility, CLAB, are used for validation of the decay heat power, while comparisons to the results of the international program ARIANE are used to demonstrate the capability of CMS5/SNF to accurately predict isotopic compositions. The paper shows the results calculated with ENDF/B-VIII.R0, and the effect on the spent fuel characteristics is evaluated by comparisons to the earlier ENDF/B-VII.R1 results.