bluuebunny/crossref_metadata_2025 huggingface dataset:
New compact MIMO antenna for 5G, WiMAX and WLAN technologies with dual polarisation and element diversity
Authors: Oliveira João Guilherme D. , D’Assunção Junior Adaildo G. , Silva Neto Valdemir P. , D’Assunção Adaildo G.
Published: March 2021

A new MIMO antenna configuration, with two different elements is proposed. The first element with a T‐shaped monopole is fed by a microstrip line and the second element is a square patch fed by electromagnetic coupling. The antenna configuration is used to provide good decoupling between the elements and to ensure antenna diversity. The antenna is designed to operate in the UWB 3.1–5.2 GHz lower‐band technology and also in the lower band of 5G technology at 3.5 GHz. The antenna design steps are presented and discussed. Simulation and design are performed using Ansoft HFSS software and the generalisation of the wave concept iterative procedure (WCIP) modified to account for the MIMO antenna structure analysis. A prototype is fabricated for comparison purposes and good agreement is observed between simulation and measurement results.
A folded monopole antenna with variable input impedance by connecting additional elements
Authors: Nakagawa Yuta , Mizutani Tomokazu , Michishita Naobumi , Morishita Hisashi
Published: March 2021

A folded monopole antenna (FMA) with two different input impedances were investigated to develop an antenna that is robust to metal for applications in a space enclosed by metal objects. An antenna with a variable input impedance is required for improving its robustness to the metal. An FMA with a novel structure is proposed to control the input impedance using a simple configuration. The structure comprises six additional elements parallel to the FMA. However, the number is not limited to six. Some additional elements are electrically connected or disconnected depending on the requirement. Method of moment (MoM) and characteristics mode analysis (CMA) are used in the simulation. The MoM results demonstrate that the input impedance can be adjusted in a step‐wise manner based on the number of additional elements connected to the FMA. This result is similar to that of the input impedance of an FMA with different strip widths considering impedance step‐up ratios (SURs). Furthermore, the change in the antenna characteristics owing to the non‐connected additional elements is minimal. The CMA results reveal that the proposed antenna has the same operation mode as the FMA with different strip widths considering impedance SURs.
PH‐RLS: A parallel hybrid recursive least square algorithm for self‐mixing interferometric laser sensor
Authors: Khan Zohaib A , Hussain Tassadaq , Zabit Usman , Usman Muhammad , Ayguade Eduard
Published: March 2021

The authors present the parallel‐hybrid recursive least square (PH‐RLS) algorithm for an accurate self‐mixing interferometric laser vibration sensor coupled with an accelerometer under industrial conditions. Previously, this was achieved by using a conventional RLS algorithm to cancel the parasitic vibrations where the sensor itself is not in the stationary environment. This algorithm operates in sequential mode and due to its compute and data‐intensive nature, the algorithm does not work for real‐time applications, hence requires parallel computing. Therefore, the existing conventional RLS C program is parallelized by using hybrid OpenACe C/MPI (Open Accelerators/Message Passing Interface) parallel programming models and tested on Barcelona Supercomputing Center CTE‐Power9 Supercomputer. The computational performance of the proposed PH‐RLS algorithm is compared with the existing conventional RLS code by executing on multi distributed processors and uni‐core processor architecture, respectively. While comparing the performance of conventional RLS with a PH‐RLS algorithm on eight nodes of CTE‐Power9 supercomputer, the results show that the PH‐RLS algorithm gets 5857 times of performance improvement as compared to the conventional RLS implementation on a single node system. The results show that the proposed PH‐RLS also gives a scalable performance for a different range of vibration signals, making it a suitable choice for real‐time self‐mixing interferometer sensing systems working under industrial conditions.
Contact‐free dielectric response measurement based on limit fitting by neural network
Authors: Shen Zhongyi , Yang Lijun , Tang Hanwei , Lai Yijun
Published: March 2021

Frequency domain spectroscopy (FDS) is widely used in analysis of insulation condition of dielectric material. The traditional contact method is susceptible to the impact of the contact state between the test sample and the electrode, which is also difficult to ensure the accuracy and repeatability of the test results. Using the method of sputtering gold on the surface of the sample is an effective way to avoid this problem though, this processing method is time‐consuming and high‐cost. This paper presents a method based on limit fitting by neural network to realize contact‐free dielectric response measurement, which can eliminate the distortion effect of the air gap introduced by the uneven surface of dielectric material. Cross linked polyethylene (XLPE) is chosen as the test object to verify this method: in the domain of frequency = 1–1000 Hz, comparing with the test results of sample treatment by gold sputtering, the average error of frequency domain spectroscopy data in traditional method is 10%, while the new method is only 1%. Meanwhile, this paper analyses the cause of the errors in each method.
Optimal peer‐to‐peer energy sharing between grid‐connected prosumers with different demand profiles and renewable energy sources
Authors: Kusakana Kanzumba
Published: March 2021

A model is developed to optimise power sharing between two grid‐connected prosumers that incorporates photovoltaic and wind energy conversion systems operating in a peer‐to‐peer (P2P) energy‐sharing arrangement. The city of Durban, South Africa, where wind and solar resources are abundant, is selected as a case study to analyse power flows between selected prosumers. The model optimally manages power flows among micro renewables‐based energy generators while minimising the total cost of energy purchased from the power utility under a time‐variable pricing structure. To evaluate the economic feasibility of the suggested peer‐to‐peer energy‐sharing arrangement, a lifecycle cost analysis is conducted to determine when the proposed system will break even, in terms of money spent less achievable salvage value, using the suggested prosumers instead of providing power exclusively from the grid to satisfy load demands. The analysis predicts that the breakeven point will occur after 4.3 years at $13,500, with a projected saving at the end of the 20‐year lifecycle of approximately $60,536.82, or 47.42%. Furthermore, the ‘true’ payback period method is used to assess the economic behaviour of the proposed system with P2P energy‐sharing capabilities and indicates that the total investment cost would be recovered in 8.76 years. These results show that the optimally controlled peer‐to‐peer energy‐sharing scheme is economically feasible in the South African context and may be applied in any global location with similar operating conditions.
Abundances of neutron-capture elements in thin- and thick-disc stars in the solar neighbourhood
Authors: Tautvaišienė G. , Viscasillas Vázquez C. , Mikolaitis Š. , Stonkutė E. , Minkevičiūtė R. , Drazdauskas A. , Bagdonas V.
Published: March 2021

Aims. The aim of this work is to determine abundances of neutron-capture elements for thin- and thick-disc F, G, and K stars in several selected sky fields near the north ecliptic pole and to compare the results with the Galactic chemical evolution models, to explore elemental gradients according to stellar ages, mean galactocentric distances, and maximum heights above the Galactic plane.

Methods. The observational data were obtained with the 1.65 m telescope at the Molėtai Astronomical Observatory and a fibre-fed high-resolution spectrograph covering a full visible wavelength range (4000−8500 Å). Elemental abundances were determined using a differential line-by-line spectrum synthesis using the TURBOSPECTRUM code with the MARCS stellar model atmospheres and accounting for the hyperfine-structure effects.

Results. We determined abundances of Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, and Eu for 424 thin- and 82 thick-disc stars. The sample of thick-disc stars shows a clearly visible decrease in [Eu/Mg] with increasing metallicity compared to the thin-disc stars, bringing more evidence of a different chemical evolution in these two Galactic components. Abundance correlation with age slopes for the investigated thin-disc stars are slightly negative for the majority of s-process dominated elements, while r-process dominated elements have positive correlations. Our sample of thin-disc stars with ages spanning from 0.1 to 9 Gyr gives the [Y/Mg] = 0.022 (±0.015)−0.027 (±0.003)⋅age [Gyr] relation. However, for the thick-disc stars, when we also took data from other studies into account, we found that [Y/Mg] cannot serve as an age indicator. The radial abundance-to-iron gradients in the thin disc are negligible for the s-process dominated elements and become positive for the r-process dominated elements. The vertical gradients are negative for the light s-process dominated elements and become positive for the r-process dominated elements. In the thick disc, the radial abundance-to-iron slopes are negligible, and the vertical slopes are predominantly negative.
Topical oro-dispersible budesonide tablets for stricture prevention after near circumferential ESD for esophageal squamous cell cancer – a case report
Authors: Mathies Daniel , Oyama Tsuneo , Steinbrück Ingo , Dumoulin Franz Ludwig
Published: March 2021

Background Endoscopic resection is the treatment of choice for early esophageal cancers. However, resections comprising more than 70–80 % of the circumference are associated with a high risk of stricture formation. Currently, repetitive local injections and/or systemic steroids are given for prevention.

Case report We present here the case of a 78-year-old male patient who had a near circumferential endoscopic submucosal dissection for a pT1a mm, L0, V0, R0, G2 esophageal squamous cell cancer. At the end of endoscopic resection, 80 mg of triamcinolone was injected locally. The patient was then treated with oro-dispersible budesonide tablets (2 × 1 mg/day) and nystatin (4 × 100 000 I.E.) for 8 weeks. This treatment resulted in complete healing without any stricture formation and did not result in any complications.

Discussion Treatment with orodispersible budesonide tablets could help prevent strictures after large endoscopic resections in the esophagus.
Use of Electronic Health Records to Identify Exposure-Response Relationships in Critically Ill Children: An Example of Midazolam and Delirium
Authors: Zimmerman Kanecia O. , Spears Tracy G. , Cobbaert Marjan , Boakye-Agyeman Felix , Wu Huali , Cohen-Wolkowiez Michael , Watt Kevin M. , Benjamin Daniel K. , Becker Mara L. , Traube Chani , Smith P. Brian
Published: March 2021

Adverse drug events are common in critically ill children and often result from systemic or target organ drug exposure. Methods of drug dosing and titration that consider pharmacokinetic alterations may improve our ability to optimally dose critically ill patients and reduce the risk for drug-related adverse events. To demonstrate this possibility, we explored the exposure-response relationship between midazolam and delirium in critically ill children. We retrospectively examined electronic health records (EHRs) of critically ill children <18 years of age hospitalized in the pediatric intensive care unit at Duke University; these children were administered midazolam during mechanical ventilation and had ≥1 Cornell Assessment of Pediatric Delirium (CAPD) score. We used individual-level data extracted from the EHR and a previously published population pharmacokinetic (PK) model developed in critically ill children to simulate plasma concentrations at the time of CAPD scores in 1,000 representative datasets. We used multilevel repeated measures models, with clustering at patient and simulation levels, to evaluate the associations between measures of drug exposure (e.g., concentration and area under concentration time curve) and delirium scores. We included 61 children, median age 1.5 years (range = 0.1–16.3), with 181 CAPD assessments. We identified similarities between simulated Empirical Bayesian parameter estimates from the EHR cohort and those from the PK model population. We identified a stronger association between drug concentration at the time of score and CAPD scores (coefficient 1.78; 95% confidence interval: 1.66–1.90) compared with cumulative dose per kilogram and CAPD scores (coefficient −0.01; 95% confidence interval: −0.01 to −0.01). EHR and PK models can be leveraged to investigate exposure-response relationships in critically ill children.
Determining the band alignment of copper-oxide gallium-oxide heterostructures
Authors: Benz S. L. , Becker M. , Polity A. , Chatterjee S. , Klar P. J.
Published: March 2021

The copper oxides cuprite (Cu2O) and tenorite (CuO) are ideal candidates for solar cells as they promise high conversion efficiencies according to the Shockley–Queisser limit. However, both cannot readily be doped n-type, thus hampering the formation of all copper oxide p–n junctions for solar cell applications. The combination of the copper oxides with gallium sesquioxide, in particular, α-Ga2O3 and β-Ga2O3, is considered to be an excellent heterojunction system for overcoming this challenge. In such a p–n junction, the p-type copper oxide layer will act as an absorber and the transparent n-type gallium sesquioxide will act as a window layer. In these devices, the band alignment at the internal interface is crucial for the device performance. Here, we study the band alignments of four different copper oxide–gallium sesquioxide heterostructures by x-ray photoelectron spectroscopy. Within the experimental margin of error, a Cu2O/α-Ga2O3 heterostructure appears to offer the most favorable band alignment for photovoltaic applications.
Utilizing relativistic time dilation for time-resolved studies
Authors: Daoud Hazem , Miller R. J. Dwayne
Published: March 2021

Time-resolved studies have so far relied on rapidly triggering a photo-induced dynamic in chemical or biological ions or molecules and subsequently probing them with a beam of fast moving photons or electrons that crosses the studied samples in a short period of time. Hence, the time resolution of the signal is mainly set by the pulse duration of the pump and probe pulses. In this paper, we propose a different approach to this problem that has the potential to consistently achieve orders of magnitude higher time resolutions than what is possible with laser technology or electron beam compression methods. Our proposed approach relies on accelerating the sample to a high speed to achieve relativistic time dilation. Probing the time-dilated sample would open up previously inaccessible time resolution domains.
Carbon dioxide hydrate in a microfluidic device: Phase boundary and crystallization kinetics measurements with micro-Raman spectroscopy
Authors: Wells Jonathan D. , Chen Weiqi , Hartman Ryan L. , Koh Carolyn A.
Published: March 2021

Various emerging carbon capture technologies depend on being able to reliably and consistently grow carbon dioxide hydrate, particularly in packed media. However, there are limited kinetic data for carbon dioxide hydrates at this length scale. In this work, carbon dioxide hydrate propagation rates and conversion were evaluated in a high pressure silicon microfluidic device. The carbon dioxide phase boundary was first measured in the microfluidic device, which showed little deviation from bulk predictions. Additionally, measuring the phase boundary takes on the order of hours compared to weeks or longer for larger scale experimental setups. Next, propagation rates of carbon dioxide hydrate were measured in the channels at low subcoolings (<2 K from phase boundary) and moderate pressures (200–500 psi). Growth was dominated by mass transfer limitations until a critical pressure was reached, and reaction kinetics limited growth upon further increases in pressure. Additionally, hydrate conversion was estimated from Raman spectroscopy in the microfluidics channels. A maximum value of 47% conversion was reached within 1 h of a constant flow experiment, nearly 4% of the time required for similar results in a large scale system. The rapid reaction times and high throughput allowed by high pressure microfluidics provide a new way for carbon dioxide gas hydrate to be characterized.
Suppressing antiferromagnetic coupling in rare-earth free ferromagnetic MnBi-Cu permanent magnet
Authors: Choi Minyeong , Hong Yang-Ki , Won Hoyun , Mankey Gary J. , Yeo Chang-Dong , Lee Woncheol , Jung Myung-Hwa , Lee Taegyu , Lee Jong-Kook
Published: March 2021

Rare-earth free, ferromagnetic MnBi shows a positive temperature coefficient of coercivity from room temperature to 400 K and energy product (BH)max of 17.7 MGOe at 300 K. However, MnBi undergoes a first-order structural phase transformation from a ferromagnetic low-temperature phase (LTP) to a paramagnetic high-temperature phase at 613 K below the Curie temperature (Tc) of 716 K. The transformation is attributed to Mn diffusion into the interstitial site of LTP MnBi unit cell. Interstitial Mn antiferromagnetically couples with the Mn at lattice 2a site, lowering the magnetization. Cu-occupied bipyramidal sites are investigated as a possible means to suppress Mn diffusion into the bipyramidal sites using first-principles calculations based on the density functional theory. Saturation magnetization, magnetocrystalline anisotropy constant (K), and Tc of (Mn0.5Bi0.5)100−xCux (x = 0–33) are reported. The magnetocrystalline anisotropy changes to the out-of-plane direction (x = 13) from the in-plane direction (x = 0.0). Tc decreases gradually to 578 K at x = 33 from 716 K at x = 0.0. The calculations show a slightly lower (BH)max of 15.6 MGOe while it is expected that Cu-occupied interstitial sites will significantly suppress Mn diffusion and raise the temperature of the phase transformation.
Capillary driven flow in oval tubes under microgravity
Authors: Chen Shangtong , Ye Zhijun , Duan Li , Kang Qi
Published: March 2021

The capillary driven flow of a liquid in a tube of elliptical cross section under microgravity is studied in this paper. All the factors including the dynamic contact angle between the liquid and the tube wall, the pressure loss caused by convection, the viscous resistance in the tube and the reservoir, and the curved liquid surface in the reservoir are considered. The equation of capillary driven flow in the tube of elliptical cross section is derived. The flow equation can be transformed into an equation that combines external forces on the control body in the tube. In the case of low Ohnesorge (Oh) numbers, the flow behavior is divided into three time domains by using the capillary force as the driving force that balances with the inertial force in the reservoir, the convective pressure loss in the reservoir, and the viscous resistance in the tube in the three domains, respectively. The liquid climbing height in these three sections is proportional to t2, t, and t, respectively. However, in the case of high Oh numbers, the flow is divided into two regions, something which has not been proposed in previous work about capillary driven flow in cylinder tubes. This study is verified by drop tower experiments and numerical simulation with the volume of fluid method.
New method for time alignment and time calibration of the TOFOR time-of-flight neutron spectrometer at JET
Authors: Eriksson B. , Conroy S. , Ericsson G. , Eriksson J. , Giacomelli L. , Hjalmarsson A. , Weiszflog M. ,   JET Contributors
Published: March 2021

The TOFOR time-of-flight (TOF) neutron spectrometer at the Joint European Torus (JET) is composed of 5 start (S1) and 32 stop (S2) scintillation detectors. Recently, the data acquisition system (DAQ) of TOFOR was upgraded to equip each of the 37 detectors with its own waveform digitizer to allow for correlated time and pulse height analysis of the acquired data. Due to varying cable lengths and different pulse processing pathways in the new DAQ system, the 160 (5 · 32) different TOF pairs of start–stop detectors must be time-aligned to enable the proper construction of a summed TOF spectrum. Given the time (energy) resolution required by the entire spectrometer system to measure different plasma neutron emission components, it is of importance to align the detector pairs to each other with sub-nanosecond precision. Previously, the alignment partially depended on using fusion neutron data from Ohmic heating phases of JET experimental pulses. The dependence on fusion neutron data in the time alignment process is, however, unsatisfactory as it involves data one would wish to include in an independent analysis for physics results. In this work, we describe a method of time-aligning the detector pairs by using gamma rays. Given the known geometry and response of TOFOR to gamma rays, the time alignment of the detector pairs is found by examining gamma events interacting in coincidence in both S1–S1 and S1–S2 detector combinations. Furthermore, a technique for separating neutron and gamma events in the different detector sets is presented. Finally, the time-aligned system is used to analyze neutron data from Ohmic phases for different plasma conditions and to estimate the Ohmic fuel ion temperature.
Simple extended lattice Boltzmann methods for incompressible viscous single-phase and two-phase fluid flows
Authors: Suzuki Kosuke , Inamuro Takaji , Nakamura Aoi , Horai Fuminori , Pan Kuo-Long , Yoshino Masato
Published: March 2021

The lattice Boltzmann method (LBM) is a numerical method with second-order spatial accuracy for incompressible viscous fluid flows based on an analogy with the kinetic theory of gases. Recently, the collision model of the LBM has become more and more complicated as its numerical stability has been enhanced. In this paper, conversely, we propose simple extended LBMs having good numerical stability with simple collision models by using the lattice kinetic scheme (LKS), which is an extended LBM. First, several schemes for single-phase flows based on the LKS are presented. The LKS is a simple stable scheme but has higher-order dissipation errors in the calculation of high-Reynolds-number flows. To solve this problem, the LKS is improved by using the linkwise artificial compressibility method (LWACM). Then, the numerical stability and accuracy of the LBM, the LKS, the LWACM, and the improved LKS are compared in a simulation of a doubly periodic shear layer at high Reynolds number with low-resolution grids. Next, a simple scheme for two-phase flows with large density ratio is constructed on the basis of the LKS and the improved LKS. The scheme is stable even for two-phase flows with large density ratio. The validation of the scheme is studied in a simulation of a binary droplet collision.
Reversible elastocaloric effect related to B2–R transformation in Ni50.5Ti49.5 alloy
Authors: López-Medina Margarita , Hernández-Navarro Fernando , Flores-Zúñiga Horacio , Soto-Parra D. E.
Published: March 2021

In Ti–Ni alloys, the low hysteresis emanating from the B2 ↔ R transition enables a fine control of reversibility in elastocaloric effects when there are lower values of applied stress. In this paper, we reported a Ni50.5Ti49.5 alloy synthesized by arc melting promoting the R phase. Using energy dispersive x-ray analysis, differential scanning calorimetry, x-ray diffraction, and elongation measures as a function of temperature, we have studied properties in an isolated R phase. We observe that there are similarities between the isothermal entropy change curves and the reversible adiabatic temperature changes, where a maximum value of reversible isothermal entropy of 14.6 J kg−1 K−1 at 310 K is obtained when a stress of 222 MPa is applied. We show that precipitates formed on the R phase play a role in the elastic behavior affecting the values of adiabatic temperature change.
Kleine-Levin syndrome is associated with birth difficulties and genetic variants in the
TRANK1
gene loci
Authors: Ambati Aditya , Hillary Ryan , Leu-Semenescu Smaranda , Ollila Hanna M. , Lin Ling , During Emmanuel H. , Farber Neal , Rico Thomas J. , Faraco Juliette , Leary Eileen , Goldstein-Piekarski Andrea N. , Huang Yu-Shu , Han Fang , Sivan Yakov , Lecendreux Michel , Dodet Pauline , Honda Makoto , Gadoth Natan , Nevsimalova Sona , Pizza Fabio , Kanbayashi Takashi , Peraita-Adrados Rosa , Leschziner Guy D. , Hasan Rosa , Canellas Francesca , Kume Kazuhiko , Daniilidou Makrina , Bourgin Patrice , Rye David , Vicario José L. , Hogl Birgit , Hong Seung Chul , Plazzi Guiseppe , Mayer Geert , Landtblom Anne Marie , Dauvilliers Yves , Arnulf Isabelle , Mignot Emmanuel Jean-Marie
Published: March 2021

Significance

Genetic markers in
TRANK1
gene and its vicinity have been weakly associated with bipolar disorder and schizophrenia (10% increased risk). We found that the same polymorphisms are associated with Kleine-Levin syndrome (50% increased risk), a rare sleep disorder characterized by recurrent episodes of severe hypersomnia and cognitive abnormalities. Response to lithium treatment is suggestive of a pathophysiological overlap between KLS and bipolar disorder. The study also shows that variants in the
TRANK1
gene region may predispose to KLS when patients have had a difficult birth, suggesting that
TRANK1
gene region modulates newborns’ response to brain injury, with consequences for mental and neurological health in adulthood. Another possibility may be that the polymorphism impacts birth and KLS.
Rapid initiation of cell cycle reentry processes protects neurons from amyloid-β toxicity
Authors: Ippati Stefania , Deng Yuanyuan , van der Hoven Julia , Heu Celine , van Hummel Annika , Chua Sook Wern , Paric Esmeralda , Chan Gabriella , Feiten Astrid , Fath Thomas , Ke Yazi D. , Haass Nikolas K. , Ittner Lars M.
Published: March 2021

Significance

The FUCCI reporter system allows live monitoring of the cell cycle via temporal expression of fluorescence markers of G0/1 or S/G2/M cell cycle phases. We found transient FUCCI reporter activity in naive neurons but not cell division, suggesting that the postmitotic state of neurons is rather a dynamic process of suppressing the cell cycle than a definite G0 state. Exposing neurons to amyloid-β resulted in death of the majority of neurons without cell cycle contribution. A subset of neurons that entered early stages of cell cycle and maintained this state were protected from amyloid-β-induced cell death. Consistently, we found high FUCCI reporter activity in the brains of mice that form amyloid-β through transgenic expression of the amyloid-β precursor protein.
A switch from noncanonical to canonical Wnt signaling stops neuroblast migration through a Slt–Robo and RGA-9b/ARHGAP–dependent mechanism
Authors: Rella Lorenzo , Fernandes Póvoa Euclides E. , Mars Jonas , Ebbing Annabel L. P. , Schoppink Luc , Betist Marco C. , Korswagen Hendrik C.
Published: March 2021

Significance

Cell migration is a central process in development, homeostasis, and disease. Among the extracellular signaling molecules that control this process are members of the Wnt family of secreted glycoproteins, which trigger distinct canonical and noncanonical pathways in responding cells. Studies in vertebrates have shown that these pathways can antagonistically regulate migration, but how they functionally interact is not known. Using the migration of the
C. elegans
QR neuroblast descendants as a tractable model system, we found that the two pathways converge on activators and inhibitors of the Rho family of small GTPases that mediate cell migration. Our results show that through this cross-talk mechanism, Wnt pathways can interact to tightly regulate the migration of cells to their final destinations.
“Diversity is a code word. And what it means is white genocide!”
Authors: Bourou Maria
Published: March 2021

Although the language of extreme nationalism has been well-investigated, no studies have been concerned with the cinematic representation of racism. This article discusses the most prominent rhetorical strategies employed by neofascist characters in four race-related movies. Adopting a CDA perspective, it examines instances of hate speech targeted at minorities and identifies how immigrants and other social groups are constructed as antagonistic. Direct verbal attacks against minorities were found to be particularly humiliating due to the recurrent use of racial slurs, culture-specific stereotypes, directives and contemptuous remarks targeting the immigrants’ background. Deemed to possess an innate inclination to criminality, immigrants were presented as a threat to white rights, jobs and public safety. Modern multicultural environments, resembling dystopias, were characterised as the ideal places within which unlawfulness could thrive. The government was held responsible for abandoning the native population that was inflicted by ‘anti-white racism’. Finally, xenophobia and antisemitism intersected with gender-related bias.
Impoliteness in hip-hop music
Authors: Delis Panagiotis
Published: March 2021

The aim of this paper is to examine the functionality of impoliteness strategies as rhetorical devices employed by acclaimed African American and White hip-hop artists. It focuses on the social and artistic function of the key discursive element of hip-hop, namely aggressive language. The data for this paper comprise songs of US African American and White performers retrieved from the November 2017 ‘TOP100 Chart’ for international releases on Spotify.com. A cursory look at the sub-corpora (Black male/ Black female/ White male/ White female artists’ sub-corpus) revealed the prominence of the ‘use taboo words’ impoliteness strategy. The analysis of impoliteness instantiations by considering race and gender as determining factors in the lyrics selection process unveiled that both male groups use impoliteness strategies more frequently than female groups. It is also suggested that Black male and White female singers employ impoliteness to resist oppression, offer a counter-narrative about their own experience and self (re)presentation and reinforce in group solidarity.
“Congratulations! You just won the title for ‘worse Tinder opening line’”
Authors: Kavroulaki Evanthia
Published: March 2021

Often preferred to its face-to-face counterpart, online dating has transformed the way we perceive practices relevant to meeting people, mostly because it offers “a wider pool of potential partners” (Heino, Ellison, and Gibbs 2010, 428). Despite its popularity, however, online dating is an under-researched area in general, crucially in linguistics. Looking at (mostly unsuccessful) naturally occurring initial interactions that have taken place on the popular Tinder application, the aim of this study is to gain some insights into the relationship among language aggression, impoliteness and communication failure in the context of flirting on Tinder. Results show that the most common way that users initiate interaction in this dataset is through sexually loaded language, which seems to be understood as a breach of the norms of appropriateness for first-time contact. Although Tinder has no manual to prescribe what should or should not be said in interaction, it transpires from the data that avoiding overstepping in terms of sexual matters (i.e. refraining from using sexually loaded language and/or innuendos) functions as an unwritten law which sparks impoliteness when not followed. Resulting impoliteness manifests itself mostly through the strategies of sarcasm and ignoring/snubbing the other, used to counteract (perceived) inappropriateness. Tracing this escalation of non-cooperative practices, from inappropriateness to impoliteness, also provides the opportunity to examine the emergence of playfulness and creativity as language behaviours interwoven with aggression. Therefore, online dating seems to lend itself well to the study of impoliteness and violation of norms of appropriate behaviour, providing opportunities for an expansion of contexts for linguistic analysis.
Disagreements in a feminist digital safe space
Authors: Krikela Sofia
Published: March 2021

Research on impoliteness has underlined the need for multidisciplinary approaches to impoliteness (Sifianou 2019a). In this article, I adopt the concept of “safe space”, as discussed in works on feminist digital media (Clark-Parsons 2018;Rentschler 2014), to explore how impoliteness relates to identity construction and the negotiation of power dynamics in the context of a Greek feminist website, constructed as a safe space. Both the concept of “safe space” and discursive and relational approaches to impoliteness (Angouri and Locher 2012;Graham 2007;Locher and Watts 2005,2008) relate to norms of appropriate behaviour in particular contexts and relational issues, such as power and identity.

The data for this article comprise comments posted in discussions taking place in the Greek website ofA, mpa, in which participants became involved in disagreements.Culpeper’s (2010)framework for conventionalised impoliteness formulae is the starting point of the analysis, which takes a discourse analytical approach to investigate the intersection of identity and power in the site. Results show that criticisms and challenging questions are linked to the identification of participants with particular feminist positions, and to the negotiation of the power distribution between the administrator and themselves. Furthermore, the paradoxical nature of safe spaces plays an important role in these processes, as the use of impoliteness points to the negotiation of the norms for interaction among participants and reveals the struggle between individual expression and maintenance of safety.
Impoliteness across social media platforms
Authors: Teneketzi Korallia
Published: March 2021

This paper responds to the call for more comparative research across online social media platforms (Graham and Hardaker 2017, 808) and examines discourse across two such platforms, YouTube and Reddit. More specifically, it attempts to investigate whether the affordances of these platforms have an impact on the amount and form of impoliteness employed by their users.

Data on a highly contested topic (the July 2018 wildfires in Attica, Greece) is studied both qualitatively and quantitatively. First, small but representative samples are qualitatively analyzed on the basis of the two major impoliteness types: implicational and conventionalized and their subcategories. In addition, swearword keywords extracted by means of corpus analysis tools are analyzed. It is shown that YouTube involves a great deal of (conventionalized) impoliteness (Culpeper 2011a) which could be due to factors such as the total absence of moderation, of post length limit and of detailed personal profiles as well as the presence of videos as stimuli for interaction. Considerably less impoliteness appears on Reddit, whose forum-like nature makes it a place that mostly invites civil interaction. Implicationally impolite (Culpeper 2011a) posts outnumber conventionally impolite ones, perhaps owing to the heavy moderation, the existence of public profiles and the size and coherence of the user community. It is concluded that, due to their characteristics, platforms seem to attract a certain userbase with its own motives and mindset, which in turn shape the impoliteness found within them.
Lose it to use it
Authors: Haddix Seth G. , Rasband Matthew N.
Published: March 2021

In this issue, Wang et al. (2021. J. Cell Biol.https://doi.org/10.1083/jcb.201911114) describe a phenomenon in which neuromuscular junction synapse elimination triggers myelination of terminal motor axon branches. They propose a mechanism initiated by synaptic pruning that depends on synaptic activity, cytoskeletal maturation, and the associated anterograde transport of trophic factors including Neuregulin 1-III.
Programmable droplet actuating platform using liquid dielectrophoresis
Authors: Frozanpoor Iman , Cooke Michael , Racz Zoltan , Bossons Ian , Ambukan Vibin , Wood David , Gallant Andrew , Balocco Claudio
Published: March 2021

Droplet motion has been a long-standing interest in microfluidics as it is often limited by the high operating voltages, which hampers the development of consumer applications. Forces generated by liquid dielectrophoresis (L-DEP) can enhance surface wetting, without requiring chemical modification or surface texturing. This work presents a droplet actuating platform to control the wetting behaviour of water droplets using L-DEP. The exploitation of high electric fields at the droplet solid–liquid interface reduced the operating voltages. The operating voltage can be further reduced, to as low as 30 V, by introducing a lubricant layer to minimise the droplet contact angle hysteresis, thus requiring a smaller L-DEP bulk force. The outcomes of this study will provide a new pathway for developing energy-efficient and reliable droplet actuating platforms to clean a variety of surfaces. A particular interest will be the application of this system in the automobile sector, for instance, to clean headlamps, sensors, cameras, door mirrors, front side glass, and rear screen.
Chemical kinetics and density measurements of OH in an atmospheric pressure He + O2 + H2O radiofrequency plasma
Authors: Brisset Alexandra , Gibson Andrew R , Schröter Sandra , Niemi Kari , Booth Jean-Paul , Gans Timo , O’Connell Deborah , Wagenaars Erik
Published: March 2021

This work presents experiments and modelling of OH densities in a radio-frequency driven atmospheric-pressure plasma in a plane-parallel geometry, operated in helium with small admixtures of oxygen and water vapour (He + O2 + H2O). The density of OH is measured under a wide range of conditions by absorption spectroscopy, using an ultra-stable laser-driven broad-band light source. These measurements are compared with 0D plasma chemical kinetics simulations adapted for high levels of O2 (1%). Without O2 admixture, the measured density of OH increases from 1.0 × 1014 to 4.0 × 1014 cm−3 for H2O admixtures from 0.05% to 1%. The density of atomic oxygen is about 1 × 1013 cm−3 and grows with humidity content. With O2 admixture, the OH density stays relatively constant, showing only a small maximum at 0.1% O2. The simulations predict that the atomic oxygen density is strongly increased by O2 addition. It reaches ∼1015 cm−3 without humidity, but is limited to ∼1014 cm−3 beyond 0.05% water content. The addition of O2 has a weak effect on the OH density because, while atomic oxygen becomes a dominant precursor for the formation of OH, it makes a nearly equal contribution to the loss processes of OH. The small increase in the density of OH with the addition of O2 is instead due to reaction pathways involving increased production of HO2 and O3. The simulations show that the densities of OH, O and O3 can be tailored relatively independently over a wide range of conditions. The densities of O and O3 are strongly affected by the presence of small quantities (0.05%) of water vapour, but further water addition has little effect. Therefore, a greater range and control of the reactive species mix from the plasma can be obtained by the use of well-controlled multiple gas admixtures, instead of relying on ambient air mixing.
Implicit and coupled fluid plasma solver with adaptive Cartesian mesh and its applications to non-equilibrium gas discharges
Authors: Arslanbekov Robert R , Kolobov Vladimir I
Published: March 2021

We present a new fluid plasma solver with adaptive Cartesian mesh (ACM) based on a full-Newton (nonlinear, implicit) scheme for non-equilibrium gas discharge plasma. The electrons and ions are described using drift–diffusion approximation coupled to Poisson equation for the electric field. The electron-energy transport equation is solved to account for electron thermal conductivity, Joule heating, and energy loss of electrons in collisions with neutral species. The rate of electron-induced ionization is a function of electron temperature and could also depend on electron density (important for plasma stratification). The ion and gas temperature are kept constant. The transport equations are discretized using a non-isothermal Scharfetter–Gummel scheme to resolve possible large temperature gradients in the sheaths. We demonstrate the new solver for simulations of direct current (DC) and radiofrequency (RF) discharges. The implicit treatment of the coupled equations allows using large time steps. The full-Newton method (FNM) enables fast nonlinear convergence at each time step, offering significantly improved simulation efficiency. We discuss the selection of time steps for solving different plasma problems. The new solver enables solving several problems we could not solve before with existing software: two- and three-dimensional structures of the entire DC discharges including cathode and anode regions, electric field reversals and double-layer formation, the normal cathode spot and an anode ring, moving striations in diffuse and constricted DC discharges, and standing striations in RF discharges. The developed FNM-ACM technique offers many benefits for tackling the disparity of gas discharge plasma systems' time scales and nonlinearity.
Ultralow-power instant-on photon-pair counting and photon-entanglement analysis
Authors: Liu Xinghua , Fedotov Ilya V , Liu Jiru , Maleki Yusef , Vincent Christapher , Blakley Sean M , Zheltikov Aleksei M
Published: March 2021

The latest breakthroughs in quantum technologies, such as satellite quantum communications, present new challenges, imposing stringent restrictions on weight, size, and power consumption of quantum information systems. Here, we show that nonlinear and quantum optics provides powerful resources to confront these challenges by offering attractive solutions for photon-pair counting and quantum-entanglement detection. We demonstrate a low-cost, readily miniaturizable photon-pair counting module, which consumes less than 100 μAh during a sub-10 ms power-on/off measurement cycle, thus providing a meaningful performance as a promising component for satellite quantum technologies.
QCD phase diagram at finite isospin and baryon chemical potentials with the self-consistent mean field approximation *
Authors: Wu Zu-Qing , Ping Jia-Lun , Zong Hong-Shi
Published: March 2021

The self-consistent mean field approximation of the two-flavor NJL model, with a free parameter

to reflect the competition between the "direct" channel and the "exchange" channel, is employed to study the QCD phase structure at finite isospin chemical potential

, finite baryon chemical potential

and finite temperature T, and especially to study the location of the QCD critical point. Our results show that in order to match the corresponding lattice results of isospin density and energy density, the contributions of the "exchange" channel need to be considered in the framework of the NJL model, and a weighting factor

should be taken. It is also found that for fixed isospin chemical potentials, the lower temperature of the phase transition is obtained with increasing

in the

plane, and the largest difference of the phase transition temperature with different

's appears at

. At

the temperature of the QCD critical end point (CEP) decreases with increasing

, while the critical baryon chemical potential increases. At high isospin chemical potential (

MeV), the temperature of the QCD tricritical point (TCP) increases with increasing

, and in the low temperature regions the system will transition from the pion superfluidity phase to the normal phase as

increases. At low density, the critical temperature of the QCD phase transition with different

's rapidly increases with

at the beginning, and then increases smoothly around

MeV. In the high baryon density region, the increase of the isospin chemical potential will raise the critical baryon chemical potential of the phase transition.
Belief propagation guided decimation algorithms for random constraint satisfaction problems with growing domains
Authors: Zhao Chun-Yan , Fu Yan-Rong
Published: March 2021

We propose three kinds of belief propagation (BP) guided decimation algorithms using asynchronous updating strategy to solve a prototype of random constraint satisfaction problem with growing domains referred to as model RB. For model RB, the exact satisfiability phase transitions have been established rigorously, and almost all instances are intrinsic hard in the transition region. Finding solutions of a random instance of model RB is very challenging, and the problem size is limited to 102. The BP guided decimation algorithms we proposed are called asynchronous updating belief propagation (ABP) algorithm, asynchronous updating belief propagation* (ABP*) algorithm, and asynchronous updating belief propagation with variable order (VABP) algorithm, respectively. In the BP part of the algorithms, we adopt asynchronous updating strategy to obtain the latest passing messages between constraints and variables, which can improve the convergence of BP equations. We also use a damping factor that adds the old messages with a certain weight into the new messages sent from variables to constraints, to reduce the occurrence of oscillation during the convergence of BP equations. In the ABP algorithm, we compute the marginal probability distribution of all variables according to the messages obtained after the BP equations converge, then select the most biased variable and fix its value on the component with the maximum probability. While the ABP* algorithm considers how to continue the decimation process if the BP equations do not converge. Different from the previous two algorithms, in the VABP algorithm, we first choose a random order of the variables, and then assign values to the variables according to the given order after BP converges. Experimental results suggest that the three kinds of BP guided decimation algorithms appear to be very effective in solving random instances of model RB even when the constraint tightness is close to the theoretical satisfiability threshold. To evaluate the performance of the ABP algorithm, we also provide synchronous updating BP algorithms as a comparison. The entropy of the selected variable at each time step and the average freedom of the variables at different constraint tightness are also discussed. Besides, we analyze the convergence of BP equations and the influence of the order of the selected variables in the decimation process of the BP guided decimation algorithms.
Weak Guidance, Multi-index and Exact Mode Eigenvalue Calculation for Mode Intensity Profiles in Tapers
Authors: Ek-Ek J R , Martinez-Pinon F , Perez-Sanchez G G , Offerhaus H L , Alvarez-Chavez J A
Published: March 2021

The fundamental mode intensity profile is calculated for different points along the transition of an optical fibre taper from standard size (125 μm external cladding diameter and 8 μm core diameter) down to micro (1 μm external fibre diameter) and submicro size (down to 440 nm fibre diameter) at 1550 nm operational wavelength. The first section of the taper was evaluated using weak guidance approximation, the second section was treated as a three-index layer structure (double-clad) and evaluated with eigenvalue equations for three refractive indices. An external medium being a liquid with a refractive index close to silica is being considered. The third and thinnest section of the taper was evaluated with the exact mode eigenvalue equation. The results show that the fundamental mode intensity for the third section show a discontinuity just at the fibre edge with a peak amplitude larger than the optical field at the centre of the fibre. The taper shape that complies with the adiabaticity criterion and how the mode intensity profile and the spot size (Petermann 1 definition) of the fundamental mode change along their position on the taper were determined.