bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of oxide and interface traps on electrical characteristics of post-deposition annealed HfSiO4/n-Si structures
Authors: Kahraman Aysegul , Yilmaz Ercan 
Published: February 2021

Abstract
This study presents detailed results on the modifications in chemical composition, defective bonds, crystal properties based on x-ray photoelectron spectroscopy (XPS) depth profiles and x-ray diffraction of post-deposition annealed HfSiO4/Si structure. It also leads to a link to defect centers and their effect on the electrical characteristics of MOS capacitors. The HfSiO4 films were deposited on n-Si wafers by RF magnetron sputtering and annealed at room temperature (RT), 300 °C, 700 °C, 900 °C, 1100 °C under N2 ambient. That the atomic concentration values of each element in the oxide did not change significantly depending on the annealing temperature showed that the film was deposited with high homogeneity. It was determined that the shift direction of the binding energies of Hf 4f and O 1s XPS spectra were related to the bonding preference of oxygen rather than its concentration. The increase in Hf–M and Hf–Si oxygen defective bonds decreased the binding energy of the XPS spectra. It was determined from the XPS analyses of amorphous films that Hf–Si and Si–Si oxygen defective bonds may cause the positive charge trapping, resulting in the highest negative charge trapping/positive effective oxide charge density (

Q

eff

) in the 300 °C-MOS capacitor. It was determined that Hf–Hf oxygen defective bonds may be the precursors of negative charge trapping. Interface states only contributed to the dielectric constant (k) in the RT-MOS capacitor. The

Φ

B

(barrier height) values showed that the efficiency of acceptor-like and donor-like interface states changes depending on the frequency.
Flexible piezoelectric device directly assembled through the continuous electrospinning method
Authors: Xue Bin , Zhang Feifei , Zheng Jianming , Xu Chunye 
Published: February 2021

Abstract
Flexible piezoelectric devices could be widely used as important components in the future of electronic skin, foldable screens, robotics, and more. Herein, an integrated flexible piezoelectric device based on polyurethane/silver nanowire (PU/AgNW) electrodes and a piezoelectric polyurethane/polyvinylidene fluoride-trifluoroethylene [PU/P(VDF-TrFE)] layer was assembled directly through the continuous electrospinning method. The sheet resistance of the PU/AgNW electrode is 1.4 Ω sq−1 without tensile strain, and the integrated device exhibits high flexibility, high water-vapor permeability, and excellent work stability. Furthermore, both the PU/AgNW electrode and the piezoelectric device perform with excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), attributed to the incorporation of the silver nanowires. The cross-section SEM image shows a uniform structure of the device, which implies a good connection between electrode layers and the piezoelectric layer. The open-circuit output voltage, short-circuit output current and power density of the device can reach up to 47.9 V, 31.8 μA, and 35.3 μw cm−2, respectively. This study presents a fabrication strategy for both flexible conductive electrodes and piezoelectric devices, and it shows a promising application for monitoring human-activity and harvesting energy from ambient environments.
Soft bidirectional haptic I/O module based on bi-convex patterned PVC gel
Authors: Dong-Soo Choi , Jeong SeongWon , Lee Seok-Han , Ryu SiHo , Kim Sang-Youn 
Published: February 2021

Abstract
In this paper, we propose a bidirectional soft haptic I/O module that not only senses the haptic force but also generates a mechanical vibrotactile sensation. Under external pressure, the distance between the moving plate and lower electrode layer decreases, and the bi-convex patterned poly vinyl chloride (bpPVC) gel gets compressed. These two motions make the capacitance of the proposed module change. Moreover, the application of external electric field (EF) creates an electrostatic force between the upper and lower electrode layers and generates the electric-field-induced deformation of the bpPVC gel simultaneously. As soon as the external EF disappears, the proposed module regains its original shape through the elastic restoring forces of the bpPVC gel and planar springs. Therefore, the applied AC voltage makes the proposed module vibrate. The dielectric and mechanical properties of the bpPVC gel are measured to investigate the optimal weight ratio of the PVC and plasticizers. Experiments are conducted to measure the haptic sensing and actuating performance of the proposed method. The capacitance of the proposed haptic I/O module increases from 17.4 pF to 54.8 pF when the external pressure varied from 0 kPa to 100 kPa. On the other hand, the haptic output of the proposed I/O module is observed as 0.81g (g = 9.8 m s−2) at 100 Hz. The results clearly indicate that the proposed haptic I/O module not only senses the static and dynamic pressure but also controls the amplitude of vibrotactile sensation. Owing to its mechanically soft structure, we expect that the proposed haptic I/O module has the potential to be applied or attached to various flexible/soft devices or the human body.
Evaluation of similarities and differences of LiTaO3 and LiNbO3 based on high-T-conductivity, nonlinear optical fs-spectroscopy and ab initio modeling of polaronic structures
Authors: Krampf A , Imlau M , Suhak Y , Fritze H , Sanna S 
Published: February 2021

Abstract
Different aspects of ferroelectric LiTaO3 (LT) such as polaronic defects, optical response and electrical conductivity are investigated by the most recent theoretical and experimental approaches. Comparing the results with the state-of-the-art knowledge of the widely studied LiNbO3 (LN), we evaluate the general assumption that there is little difference between the aforementioned properties of LT and LN. First-principles calculations reveal the existence of point defects in LT qualitatively compatible with the polaronic picture established in LN. Though, peculiar differences with respect to the individual binding energies and polaronic deformation can be revealed. Accordingly, (sub-)picosecond transient absorption measurements show pronounced differences in the kinetics in the sub-ps time domain of small polaron formation and, even more pronounced, in the long-term evolution identified with small polaron hopping. In contrast, (sub-)ps transient luminescence, attributed to the relaxation of self-trapped excitons in LN, shows very similar kinetics. Electrical conductivity measurements are performed in air as function of temperature. Up to about 600 °C they demonstrate similar temperature dependence for the two materials, from which rather comparable activation energies can be extracted. However, in the high-temperature range from about 600 °C to 920 °C both materials show noticeable differences. The results suggest that the fundamental microscopic understanding of LN can be in part transferred to LT. However, due to differences in structure, energetic landscape and temperature behavior, discrepancies between the two materials bear a striking potential for novel applications, even at high temperatures.
Recrystallization-mediated crack initiation in tungsten under simultaneous high-flux hydrogen plasma loads and high-cycle transient heating
Authors: Li Y. , Morgan T.W. , Vermeij T. , Vernimmen J.W.M. , Loewenhoff Th. , Hoefnagels J.P.M. , van Dommelen J.A.W. , Wirtz M. , De Temmerman G. , Verbeken K. , Geers M.G.D. 
Published: February 2021

Abstract
Tungsten and tungsten-based alloys are the leading material choices for the divertor plasma facing components (PFCs) in future fusion reactors. Recrystallization may occur when they undergo high heat loads, drastically modifying the predesigned grain structures and the associated desired mechanical properties. However, the influence of recrystallization on the thermal fatigue behavior of tungsten PFCs still remains unclear. In this study, ITER-grade tungsten was simultaneously exposed to a high-flux hydrogen plasma (∼5 × 1024 m−2 s−1) and high-cycle (104–105) transient heat loads in the linear plasma device Magnum-PSI. By correlating the surface temperature distribution, obtained by analyzing temperature-, wavelength-, and surface-dependent emissivity, and the surface modifications of the plasma exposed specimens, the crack initiation heat flux factor threshold was found to be ∼2 MW m−2 s0.5 (equivalently, ∼0.07 MJ m−2 for a 1 ms pulse). Based on electron backscatter diffraction analyses of cross-sections near the crack initiation sites, faster recrystallization kinetics near the surface compared to literature was observed and the surface cracks preferentially initiated at high angle grains boundaries (HAGBs). Upon recrystallization, the yield strength decreases which entails increasing cyclic plastic strains. The HAGBs fraction is increased, which constrains the transfer of plastic strains at grain boundaries. The recrystallization decreases the dislocation density, which promotes heterogeneous deformation. All these mechanisms explain the reduced crack initiation threshold of recrystallized tungsten compared to its as-received counterpart. The results provide new insights into the structural failure mechanisms in tungsten PFCs exposed to extreme fusion plasmas.
Onset of tearing modes in plasma termination on JET: the role of temperature hollowing and edge cooling
Authors: Pucella G. , Buratti P. , Giovannozzi E. , Alessi E. , Auriemma F. , Brunetti D. , Ferreira D.R. , Baruzzo M. , Frigione D. , Garzotti L. , Joffrin E. , Lerche E. , Lomas P.J. , Nowak S. , Piron L. , Rimini F. , Sozzi C. , Van Eester D. , JET Contributors  
Published: February 2021

Abstract
In this work the onset of tearing modes in the termination phase of plasma pulses on JET is investigated. It is shown that the broadening or the shrinking of the current density profile, as a consequence of a core hollowing or an edge cooling of the electron temperature profile, strongly increases the probability of destabilizing a 2/1 tearing mode also in absence of an external trigger (e.g. a sawtooth crash). Two parameters are defined to highlight changes in the shape of the temperature profile that can lead to MHD instabilities and an empirical stability diagram is introduced into the space of the two new parameters. A large data-set of pulses carried out in the high-current scenario at JET with ITER-like wall is analyzed and criteria for the development of disruption alerts based on the two risk indicators for MHD instabilities are discussed, taking into account the different dynamics of the observed phenomena leading to the onset of 2/1 tearing modes.
Pendulum beams: optical modes that simulate the quantum pendulum
Authors: Galvez E J , Auccapuclla F J , Qin Y , Wittler K L , Freedman J M 
Published: February 2021

Abstract
The wave equation of electromagnetism, the Helmholtz equation, has the same form as the Schrödinger equation, and so optical waves can be used to study quantum mechanical problems. The electromagnetic wave solutions for non-diffracting beams lead to the two-dimensional Helmholtz equation. When expressed in elliptical coordinates the solution of the angular part is the same as the Schrödinger equation for the simple pendulum. The resulting optical eigenmodes, Mathieu modes, have an optical Fourier transform with a spatial intensity distribution that is proportional to the quantum mechanical probability for the pendulum. Comparison of Fourier intensities of eigenmodes are in excellent agreement with calculated quantum mechanical probabilities of pendulum stationary states. We further investigate wave-packet superpositions of a few modes and show that they mimic the libration and the nonlinear rotation of the classical pendulum, including revivals due to the quantized nature of superpositions. The ability to ‘dial a wavefunction’ with the optical modes allows the exploration of important aspects of quantum wave-mechanics and the pendulum that may not be possible with other physical systems.
The instrument transfer function for optical measurements of surface topography
Authors: de Groot Peter J 
Published: February 2021

Abstract
For optical measurements of areal surface topography, the instrument transfer function (ITF) quantifies height response as a function of the lateral spatial frequency content of the surface. The ITF is used widely for optical full-field instruments such as Fizeau interferometers, confocal microscopes, interference microscopes, and fringe projection systems as a more complete way to characterize lateral resolving power than a single number such as the Abbe limit. This paper is a comprehensive review of the ITF, including standardized definitions, ITF prediction using theoretical simulations, common uses, limitations, and evaluation techniques using material measures.
Association between everyday walking activity, objective and perceived risk of falling in older adults
Authors: Jansen Carl-Philipp , Klenk Jochen , Nerz Corinna , Todd Chris , Labudek Sarah , Kramer-Gmeiner Franziska , Becker Clemens , Schwenk Michael 
Published: February 2021

Abstract

Background
older persons can be grouped according to their objective risk of falling (ORF) and perceived risk of falling (PRF) into ‘vigorous’ (low ORF/PRF), ‘anxious’ (low ORF/high PRF), ‘stoic’ (high ORF/low PRF) and ‘aware’ (high ORF/PRF). Sensor-assessed daily walking activity of these four groups has not been investigated, yet.

Objective
we examined everyday walking activity in those four groups and its association with ORF and PRF.

Design
cross-sectional.

Setting
community.

Subjects
N = 294 participants aged 70 years and older.

Methods
ORF was determined based on multiple independent risk factors; PRF was determined based on the Short Falls Efficacy Scale-International. Subjects were allocated to the four groups accordingly. Linear regression was used to quantify the associations of these groups with the mean number of accelerometer-assessed steps per day over 1 week as the dependent variable. ‘Vigorous’ was used as the reference group.

Results
average number of steps per day in the four groups were 6,339 (‘vigorous’), 5,781 (‘anxious’), 4,555 (‘stoic’) and 4,528 (‘aware’). Compared with the ‘vigorous’, ‘stoic’ (−1,482; confidence interval (CI): −2,473; −491) and ‘aware’ (−1,481; CI: −2,504; −458) participants took significantly less steps, but not the ‘anxious’ (−580 steps; CI: −1,440; 280).

Conclusion
we have integrated a digital mobility outcome into a fall risk categorisation based on ORF and PRF. Steps per day in this sample of community-dwelling older persons were in accordance with their ORF rather than their PRF. Whether this grouping approach can be used for the specification of participants’ needs when taking part in programmes to prevent falls and simultaneously promote physical activity remains to be answered in intervention studies.
The Impact of Epidemiology on Fertility and Prenatal Care During the COVID-19 Pandemic
Authors: Dionne-Odom Jodie , Klipstein Sigal 
Published: February 2021

Abstract
The emergence of the novel coronavirus disease 2019 (COVID-19) presented the field of reproductive medicine with many challenges due to an absence of data to guide clinical decision-making and inform patient counseling and management in the early days of the pandemic. Epidemiological studies rapidly filled key gaps in our understanding of the susceptibility of reproductive-aged women to the virus, transmission dynamics during pregnancy and lactation, and the effect of infection during the prenatal, pregnancy, and postpartum periods. This data guided the development of clinical guidelines written by the American Society for Reproductive Medicine as patients and clinicians navigated reproductive decisions during a time of uncertainty. We present a review of epidemiologic studies published between March and December 2020 that have directly informed prenatal and fertility care during the COVID-19 pandemic. Despite a significant increase in our knowledge base over the past year, many questions remain about the impact of COVID-19 on conception, pregnancy, fetal development, and lactation. In the future, a commitment toward inclusion of pregnant persons and those attempting pregnancy in the design of observational and interventional trials is necessary to gain earlier insights about outcomes and assist providers and patients in making data-driven decisions.
Impact of Anti-hypertensive Therapy in the Sexual Health of Men and Women: An Analysis From the SPRINT Trial
Authors: Ferreira João Pedro , Böhm Michael , Rossignol Patrick , Zannad Faiez 
Published: February 2021

Abstract

BACKGROUND
Pharmacologic anti-hypertensive (HT) treatment reduces cardiovascular risk. However, many patients are nonadherent due to perceived or real concern about sexual-related side effects.

METHODS
In a subset of the SPRINT (a randomized trial of intensive vs. standard blood-pressure control) trial, we sought to investigate the impact of anti-HT treatment on sexual activities of men and women over time, and whether this impact varied with a more or less intensive anti-HT therapy. Random-effects models for panel/longitudinal data.

RESULTS
Among the 1,268 men and 613 women included in this substudy, 862 (68%) men and 178 (29%) women declared to be engaged in sexual activity of any kind. Compared with women and men not engaged in sexual activity, those engaged were younger (64 vs. 69 years for women and 65 vs. 75 years for men). Women had an overall low satisfaction with their sexual life but their sexual health was not affected by anti-HT therapy over time nor modified by an intensive treatment. Men’s erections were slightly deteriorated over time (−0.1 to −0.2 points on a scale of 1 (worse) to 5 (best); P &lt; 0.05), but were not aggravated by intensive anti-HT therapy (P &gt; 0.05 for all).

CONCLUSIONS
Self-declared women’s sexual health was not affected by an intensive anti-HT therapy. Men reported a slight deterioration in the quality of their erections, irrespective of standard or intensive therapy. These findings may help reassuring patients about the sexual safety of intensive anti-HT therapy, therefore, potentially improving adherence to intensive therapy strategy.
A Longitudinal Mediation Model of Negative Emotionality, Coping Motives and Drinking Intensity Among Individuals Receiving Community Treatment for Alcohol Use Disorder
Authors: Votaw Victoria R , Stein Elena R , Witkiewitz Katie 
Published: February 2021

Abstract

Aims
Negative emotionality is a key domain in frameworks measuring heterogeneity in alcohol use disorder (AUD), such as the Addictions Neuroclinical Assessment (ANA). Recent research has examined the construct validity of the ANA negative emotionality domain, but has not examined whether this domain demonstrates predictive validity for drinking outcomes. In this study, we examined the association between self-reported negative emotionality at baseline and drinking intensity 1 year following AUD treatment initiation. We also assessed whether coping motives for alcohol use at 6 months following treatment initiation and changes in coping motives mediated this association.

Methods
This was a secondary data analysis of a multisite prospective study of individuals entering AUD treatment (n = 263; 61.6% male; mean age = 33.8). Measures of coping motives and drinking intensity captured those who experienced a lapse to drinking. The associations between the ANA negative emotionality domain, coping motives and drinking intensity over time were assessed using a latent growth curve mediation model.

Results
The ANA negative emotionality domain at baseline was indirectly associated with greater 7–12-month drinking intensity through higher coping motives at 6 months. Negative emotionality was not related to change in coping motives over the assessment period and change in coping motives was not related to 7–12-month drinking intensity.

Conclusions
This analysis provides evidence for the predictive validity of the ANA negative emotionality domain for coping motives and drinking intensity among treatment seekers who experienced a lapse to drinking. Coping motives may be an important target in AUD treatment among those high in negative emotionality.
A water drop-shaped slingshot in plants: geometry and mechanics in the explosive seed dispersal of Orixa japonica (Rutaceae)
Authors: Huang Lan-Jie , Fu Wen-Long 
Published: February 2021

Abstract

Background and Aims
In angiosperms, many species disperse their seeds autonomously by rapid movement of the pericarp. The fruits of these species often have long rod- or long plate-shaped pericarps, which are suitable for ejecting seeds during fruit dehiscence by bending or coiling. However, here we show that fruit with a completely different shape can also rely on pericarp movement to disperse seeds explosively, as in Orixa japonica.

Methods
Fruit morphology was observed by hard tissue sectioning, scanning electron microscopy and micro-computed tomography, and the seed dispersal process was analysed using a high-speed camera. Comparisons were made of the geometric characteristics of pericarps before and after fruit dehiscence, and the mechanical process of pericarp movement was simulated with the aid of the finite element model.

Key Results
During fruit dehydration, the water drop-shaped endocarp of O. japonica with sandwich structure produced two-way bending deformation and cracking, and its width increased more than three-fold before opening. Meanwhile the same shaped exocarp with uniform structure could only produce small passive deformation under relatively large external forces. The endocarp forced the exocarp to open by hygroscopic movement before seed launching, and the exocarp provided the acceleration for seed launching through a reaction force.

Conclusions
Two layers of water drop-shaped pericarp in O. japonica form a structure similar to a slingshot, which launches the seed at high speed during fruit dehiscence. The results suggest that plants with explosive seed dispersal appear to have a wide variety of fruit morphology, and through a combination of different external shapes and internal structures, they are able to move rapidly using many sophisticated mechanisms.
Per-sample standardization and asymmetric winsorization lead to accurate clustering of RNA-seq expression profiles
Authors: Risso Davide , Pagnotta Stefano Maria 
Published: February 2021

Abstract

Motivation
Data transformations are an important step in the analysis of RNA-seq data. Nonetheless, the impact of transformation on the outcome of unsupervised clustering procedures is still unclear.

Results
Here, we present an Asymmetric Winsorization per-Sample Transformation (AWST), which is robust to data perturbations and removes the need for selecting the most informative genes prior to sample clustering. Our procedure leads to robust and biologically meaningful clusters both in bulk and in single-cell applications.

Availability and implementation
The AWST method is available at https://github.com/drisso/awst. The code to reproduce the analyses is available at https://github.com/drisso/awst_analysis

Supplementary information
Supplementary data are available at Bioinformatics online.