bluuebunny/crossref_metadata_2025 huggingface dataset:
Implementation of colonoscopy quality monitoring in a Belgian university hospital with integrated computer-based extraction of adenoma detection rate
Authors: Ouazzani Sohaib , Lemmers Arnaud , Martinez Federico , Kindt Raphael , Le Moine Olivier , Delhaye Myriam , Arvanitakis Marianna , Demetter Pieter , Devière Jacques , Eisendrath Pierre
Published: February 2021

Background and study aims Quality in colonoscopy has been promoted in last decade with definition of different quality indicators (QI) as benchmarks. Currently, automatized monitoring systems are lacking, especially for merging pathologic and endoscopic data, which limits quality monitoring implementation in daily practice. We describe an adapted endoscopy reporting system that allows continuous QI recording, with automatic pathological data inclusion.

Material and methods We locally adapted a reporting system for colonoscopy by adding and structuring in a dedicated tab selected key QI. Endoscopic data from a reporting system and pathological results were extracted and merged in a separate database. During the initial period of use, performing physicians were encouraged to complete the dedicated tab on a voluntary basis. In a second stage, completing of the tab was made mandatory. The completeness of QI recording was evaluated across both periods. Performance measures for all endoscopists were compared to global results for the department and published targets.

Results During the second semester of 2017, a total of 1827 colonoscopies were performed with a QI tab completed in 100 % of cases. Among key QI, the cecal intubation rate was 93.8 %, the rate of colonoscopies with adequate preparation was 90.7 %, and the adenoma detection rate was 29.8 % considering all colonoscopies, irrespective of indication; 28.8 % considering screening procedures; and 36.6 % in colonoscopies performed in people older than age 50 years.

Conclusion This study shows that quality monitoring for colonoscopy can be easily implemented with limited human resources by adapting a reporting system and linking it to a pathology database.
Validated High-performance Liquid Chromatography Method for the Determination of JW5624, A New Class Of Hepatitis C Virus Inhibitor, in Rat Plasma and its Application in the Pharmacokinetic Study of JW5624
Authors: Kim Tae Kon
Published: February 2021

We developed unique small-molecule inhibitors of hepatitis C virus (HCV), which had potent activity for HCV entry inhibition and multi-genotypic antiviral activity. In this study, a sensitive and reliable method for the quantitation of JW5624 in rat plasma was developed and validated using high performance liquid chromatography. Chromatographic separation was achieved using a reversed-phase (C18) column. The mobile phase, 0.02 M ammonium acetate buffer:acetonitrile (30:70, v/v), was run at a flow rate of 1.0 mL/min, and the column eluent was monitored using an ultraviolet detector at 254 nm at room temperature. The retention times of sildenafil (an internal standard), and JW5624 were approximately 5.9 and 7.3 min, respectively. The detection limit of JW5624 in rat plasma was 0.03 μg/mL. Pharmacokinetic parameters of JW5624 was evaluated after intravenous (i. v.; at doses of 5 mg/kg) and oral (p.o.; at doses of 10 mg/kg) administration of JW5624 in rats. After p.o. administration (10 mg/kg) of JW5624, F value was approximately 71.0%. These results suggest that JW5624 can be a potential candidate drug for the development of HCV entry inhibitors.
Kidney-Pancreas Transplant Recipients Experience Higher Risk of Complications Compared to the General Population after Undergoing Coronary Artery Bypass Grafting
Authors: Perdue Jordyn M. , Ortiz Alejandro C. , Parsikia Afshin , Ortiz Jorge
Published: February 2021

This retrospective analysis aims to identify differences in surgical outcomes between pancreas and/or kidney transplant recipients compared with the general population undergoing coronary artery bypass grafting (CABG). Using Nationwide Inpatient Sample (NIS) data from 2005 to 2014, patients who underwent CABG were stratified by either no history of transplant, or history of pancreas and/or kidney transplant. Multivariate analysis was used to calculate odds ratio (OR) to evaluate in-hospital mortality, morbidity, length of stay (LOS), and total hospital charge in all centers. The analysis was performed for both nonemergency and emergency CABG. Overall, 2,678 KTx (kidney transplant alone), 184 PTx (pancreas transplant alone), 254 KPTx (kidney-pancreas transplant recipients), and 1,796,186 Non-Tx (nontransplant) met inclusion criteria. KPTx experienced higher complication rates compared with Non-Tx (78.3 vs. 47.8%, p < 0.01). Those with PTx incurred greater total hospital charge and LOS. On weighted multivariate analysis, KPTx was associated with an increased risk for developing any complication following CABG (OR 3.512, p < 0.01) and emergency CABG (3.707, p < 0.01). This risk was even higher at transplant centers (CABG OR 4.302, p < 0.01; emergency CABG OR 10.072, p < 0.001). KTx was associated with increased in-hospital mortality following emergency CABG, while PTx and KPTx had no mortality to analyze. KPTx experienced a significantly higher risk of complications compared with the general population after undergoing CABG, in both transplant and nontransplant centers. These outcomes should be considered when providing perioperative care.
Worries and concerns among healthcare workers during the coronavirus 2019 pandemic: A web-based cross-sectional survey
Authors: Sahashi Yuki , Endo Hirohisa , Sugimoto Tadafumi , Nabeta Takeru , Nishizaki Kimitaka , Kikuchi Atsushi , Matsumoto Shingo , Sato Hiroyuki , Goto Tadahiro , Hasegawa Kohei , Matsue Yuya
Published: February 2021

Healthcare workers (HCWs) treating and caring for patients with emerging infectious diseases often experience psychological distress. However, the psychological impact and behavior change of the coronavirus disease 2019 (COVID-19) pandemic among HCWs are still unknown. This study aimed to investigate the worries and concerns of HCWs regarding the COVID-19 pandemic. In this cross-sectional survey, a web-based questionnaire was distributed among HCWs working in hospitals or clinics across Japanese medical facilities from April 20 to May 1, 2020. The questionnaire comprised items on demographics, worries and concerns, perceptions regarding the sufficiency of information, and behavioral changes pertaining to the COVID-19 pandemic. A total of 4386 HCWs completed the survey; 1648 (64.7%) were aged 30–39 years, 2379 (54.2%) were male, and 782 (18.1%) were frontline HCWs, directly caring for patients with COVID-19 on a daily basis. 3500 HCWs (79.8%) indicated that they were seriously worried about the pandemic. The most frequent concern was the consequence of becoming infected on their family, work, and society (87.4%). Additionally, the majority (55.5%) had restricted social contact and almost all HCWs endorsed a shortage in personal protective equipment (median, 8/9 (interquartile range; 7–9) on a Likert scale). There was no significant difference in the degree of worry between frontline and non-frontline HCWs (8/9 (7–9) vs. 8/9 (7–9), p = 0.25). Frontline HCWs, compared to non-frontline HCWs, were more likely to have the need to avoid contact with families and friends (24.8% vs. 17.8%, p < 0.001) and indicated that they cannot evade their professional duty during the COVID-19 pandemic (9/9 (7–9) vs. 8/9 (6–9), p < 0.001). Further, the extremely low proportion of frontline HCWs reported that they would take a leave of absence to avoid infection (1.2%). In conclusions, both frontline and non-frontline HCWs expressed comparable concerns regarding the COVID-19 pandemic. Because HCWs, especially frontline HCWs, reported that they cannot be obliged to do avoid their duty, effective mental health protection strategies should be developed and implemented for HCWs.
What do our future teachers think about terrorism and politically motivated violence in the Basque Country?
Authors: Vicent Naiara , Albas Leire , Gillate Iratxe , Ibañez-Etxeberria Alex
Published: February 2021

Euskadi Ta Askatasuna—Basque Country and Freedom (ETA) was an armed organisation from the Basque Country and after it declared that it would cease violent actions and subsequently disbanded, the Basque Country has been involved in a peace process. The Adi-adian programme that is part of this process has been implemented as a part of teacher training programmes. By means of a mixed model that combines both qualitative and quantitative elements, the present study has attempted to identify the attitudes of future teachers—prior to implementation of Adi-adian—regarding terrorism and politically motivated violence that occurred in and from the Basque country since 1960, the information they have received with respect thereto, and their opinions as to how the issues are dealt with in the classroom. The results obtained reveal a generally respectful attitude toward human rights and the delegitimisation of violence; lack of satisfaction regarding the information they have received throughout their lives; and, as future teachers, a lack of certainty as to how to approach such issues in the classroom. It was noted that these future teachers had a high degree of motivation and interest with respect to these matters.
Attosecond
γ
-ray vortex generation in near-critical-density plasma driven by twisted laser pulses
Authors: Hu Yan-Ting , Zhao Jie , Zhang Hao , Lu Yu , Wang Wei-Quan , Hu Li-Xiang , Shao Fu-Qiu , Yu Tong-Pu
Published: February 2021

Ultra-short brilliant γ-rays have many potential applications in astrophysics, nuclear physics, and ultra-fast science. However, attosecond γ-ray beams with energy above 100 MeV are still very challenging. Here, we propose and numerically demonstrate an all-optical scheme to produce sub-GeV attosecond γ-rays in near-critical-density (NCD) plasma. When a left-hand circularly polarized Laguerre–Gaussian (LG) laser pulse irradiates the NCD plasma, dense attosecond electron bunches are produced, trapped by the LG laser, and accelerated to GeV energies. Subsequently, these electrons oscillate in the LG laser electric fields and emit a string of hundreds MeV attosecond (367 as) γ-ray pulses. Three-dimensional particle-in-cell simulations indicate that, at a laser intensity of 1022 W/cm2, the yield of γ-ray pulses with photon energies above 1 MeV is as high as 1013 with a peak angular momentum of 10−15 kg m2/s. This results in γ-ray vortex beams with an unprecedented peak brilliance of 1024 photons s−1 mm−2 mrad−2 per 0.1% bandwith at 1 MeV, which may offer a unique opportunity for diverse applications.
Quantifying the role of Darrieus–Landau instability in turbulent premixed flame speed determination at various burner sizes
Authors: Wang Xin , Cheng Xiaobei , Lu Hao , Xu Yishu , Liu Yang , Wang Renwei , Yao Junjie
Published: February 2021

To probe the impact of Darrieus–Landau (DL) instability on turbulent premixed flame propagation at various burner sizes, methane–air premixed flames from five Bunsen-type burners with different nozzle diameters (4 mm, 6 mm, 8 mm, 10 mm, and 12 mm) were investigated at Reynolds numbers ranging from 1000 to 8500. The flame curvatures used to identify DL instability were determined using Mie scatter images captured by a particle image velocimetry system. The flame speed was further derived by applying an asymmetric hypothesis to the images. The energy-frequency spectrum of the inflow disturbance was determined using a hot-wire anemometry system, and specific wavelet transform analysis was performed to investigate the dependence of DL instability on the proportion of effective disturbances (Ped) and quantify the role of DL instability in determining the turbulent flame speed. The results showed that the burner diameter had an obvious effect on the presence of DL instability and its role in flame propagation. The ability of DL instability to enhance the flame curvature skewness and the turbulent flame speed was closely related to Ped. Ped increased when the burner diameter increased from 6 mm to 12 mm, thus enhancing the DL instability. Changing the burner diameter also affected the interplay between DL instability and turbulence. The above interactions and their effects on the flame speed during the change of inflow disturbances could be formulated by Ped. Finally, a Ped-based correlation was proposed to describe the dependence of the turbulent flame speed on the burner size.
Motion and clustering of bonded particles in narrow solid–liquid fluidized beds
Authors: Cúñez Fernando David , Lima Nicolao Cerqueira , Franklin Erick M.
Published: February 2021

This paper presents an experimental and numerical investigation of solid–liquid fluidized beds consisting of bonded spheres in very narrow tubes, i.e., when the ratio between the tube and grain diameters is small. In narrow beds, high confinement effects have proved to induce crystallization, jamming, and different patterns, which can be intensified or modified if some grains are bonded together. In order to investigate that, we produced duos and trios of bonded aluminum spheres with a diameter of 4.8 mm and formed beds consisting either of 150–300 duos or 100–200 trios in a 25.4 mm-ID pipe, which were submitted to water velocities above those necessary for fluidization. For the experiments, we filmed the bed with high-speed and conventional cameras and processed the images, obtaining measurements at both the bed and grain scales. For the numerical part, we computed the bed evolution for the same conditions with a computational fluid dynamics–discrete element method code. Our results show distinct motions for individual duos and trios and different structures within the bed. We also found that jamming may occur suddenly for trios, where even the microscopic motion (fluctuation at the grain scale) stops, calling into question the fluidization conditions for those cases.
Measurement and analysis of the mean free path governing high-energy electron scattering in CdTe, via off-axis electron holography
Authors: Cassidy Cathal , Adaniya Hidehito , Shintake Tsumoru
Published: February 2021

The mean free path governing the scattering of high-energy electrons in cadmium telluride (CdTe) has been measured and analyzed using off-axis electron holography (OEH). In the first part of the study, the total mean free path value was determined via acquisition and aggregation of a large off-axis holography dataset at 300 kV and room temperature, yielding the value λOEH=52±7 nm. This is significantly shorter than some previously reported values obtained via different experimental techniques and theoretical calculations. To confirm the validity of the measurement and to understand the underlying physical scattering processes, the study was extended to systematically investigate the role of electron energy loss, electron scattering angle, and specimen temperature in the overall holography measurement. This allowed the observed mean free path value to be clearly decomposed into terms of electronic (inelastic) and nuclear (elastic) scattering processes in the material and enabled direct measurement of the relevant contributions. Specifically, the determined attenuation coefficients were μinel(ΔE>5eV)=5.9±1.2 μm−1 and μel(ΔE<5eV,α>3mrad)=13.5±1.2 μm−1 (full details in the main text). With appropriate consideration of the relevant scattering mechanisms, the mean free path value determined here from off-axis holography measurements is consistent with prior experimental measurements from other techniques and theoretical calculations. These insights and measurements should be of future value for quantitative holography and electron beam scattering experiments in CdTe.
Magnified heat transfer from curved surfaces: A scaling prediction
Authors: Zhao Yongling , Lei Chengwang , Patterson John C.
Published: February 2021

We report the first definitive Nusselt number scale of thermal boundary layers from curved surfaces characterized by the proposed non-dimensional curvature parameter ξ = R0/(HRa−1/4), where R0 denotes the radius of a curved surface, H denotes the corresponding finite height, and Ra denotes the global Rayleigh number of a virtual reference thermal boundary layer on a vertical flat surface. The Nusselt number scale is given by Nu ∼ ξ−1/5Ra1/4 in which Nu ∼ Ra1/4 is the scale for the flat surface case, revealing that curved thermal boundary layers could present times-of-magnitude larger heat flux with the curvature parameter being ξ ≪ 1. The velocity and thickness scales are also given by Vs∼R02/5Ra3/5H7/5κ and ΔT∼R01/5H4/5Ra1/5.
Energy-transfer quantum dynamics of HeH+ with He atoms: Rotationally inelastic cross sections and rate coefficients
Authors: Gianturco F. A. , Giri K. , González-Sánchez L. , Yurtsever E. , Sathyamurthy N. , Wester R.
Published: February 2021

Two different ab initio potential energy surfaces are employed to investigate the efficiency of the rotational excitation channels for the polar molecular ion HeH+ interacting with He atoms. We further use them to investigate the quantum dynamics of both the proton-exchange reaction and the purely rotational inelastic collisions over a broad range of temperatures. In current modeling studies, this cation is considered to be one of the possible cooling sources under early universe conditions after the recombination era and has recently been found to exist in the interstellar medium. The results from the present calculations are able to show the large efficiency of the state-changing channels involving rotational states of this cation. In fact, we find them to be similar in size and behavior to the inelastic and reaction rate coefficients obtained in previous studies, where H atoms were employed as projectiles. The same rotational excitation processes, occurring when free electrons are the collision partners of this cation, are also compared with the present findings. The relative importance of the reactive, proton-exchange channel and the purely inelastic channels is also analyzed and discussed. The rotational de-excitation processes are also investigated for the cooling kinetics of the present cation under cold trap conditions with He as the buffer gas. The implications of the present results for setting up more comprehensive numerical models to describe the chemical evolution networks in different environments are briefly discussed.
Prediction of tunable magnetoelectric properties in compositionally graded ferroelectric/ferromagnetic laminated nanocomposites
Authors: Le Minh-Tien , Lich Le Van , Shimada Takahiro , Kitamura Takayuki , Nguyen Giang Trong , Dinh Van-Hai
Published: February 2021

The advent of modern thin-film deposition approaches has ushered in a new era of designed materials with well-controlled composition distributions, e.g., compositionally graded ferroelectric (CGFE) thin films, and thereby, it is readily accessible CGFE/FM (ferromagnetic) multilayer thin films. Being recognized this emerging class of materials, in this study, we develop a phase-field model based on the Ginzburg–Landau theory that takes into account the gradient of ferroelectric (FE) compositions in order to predict material properties of CGFE/FM thin films. The developed phase-field model is applied to investigate the effect of the FE composition gradient on magnetoelectric (ME) coupling of graded Pb(1−x)SrxTiO3/CoFe2O4 laminated nanocomposites. Two types of composition gradients are considered: inward (O-type) and outward (X-type) gradients. Unusual polarization domain structures with curved domain walls are formed in CGFE layers, which are governed by the composition gradients and distinct from typical stripe domains in homogeneous counterparts. As a result, the ME effect is strongly dependent on the composition gradient. Particularly, the ME coupling in the O-type nanocomposites increases with the increasing composition gradient, while it decreases in the X-type ones. The dependence of ME coupling on the composition gradient originates from the distinguishable energy distributions in O-type and X-type nanocomposites. This work, therefore, provides a strategy to design the ME effect via the configuration of the composition gradient.
Geometrical manipulation of complex supramolecular tessellations by hierarchical assembly of amphiphilic platinum(II) complexes
Authors: Poon Jason Koon-Lam , Chen Zhen , Leung Sammual Yu-Lut , Leung Ming-Yi , Yam Vivian Wing-Wah
Published: February 2021

Significance

Despite numerous studies on the supramolecular engineering of intricate self-assembled patterns via noncovalent intermolecular interactions, it is still challenging to overcome the geometric and topological frustrations for creating complex tessellations by using geometrically simple building motifs. This work demonstrates a semi-regular rhombitrihexagonal Archimedean tiling enabled by hierarchical assembly of
C
2h
-symmetric platinum(II) amphiphiles in the bulk. Based on this finding, the rational design of introducing symmetry lowering into supramolecular tiling is achieved by coassembly strategies. The current study provides promising possibilities for the construction of complex supramolecular architectures and an in-depth understanding into the structural order and molecular organization in soft materials.
Evaluation of dual-task performance with Nintendo Wii-Fit plus in children with specific learning disabilities
Authors: Karabulut Mustafa , Bas Banu , Müjdeci Banu
Published: February 2021

Objective

The aim of this study was to evaluate postural stability with Nintendo Wii-Fit Plus in children with special learning disabilities (SLD) and also to investigate the effect of simultaneous cognitive and motor tasks on postural stability.

Methods

The study included 70 children (35 children with SLD and 35 children age-matched normal development). All children were assessed for stability on Nintendo Wii-Fit Plus platform on one-leg stance (OLS). Postural stability percentages were calculated by asking for cognitive and motor tasks simultaneously with the task of standing on OLS.

Results

Children with SLD were found to have poor postural stability scores in comparison with children with normal development with Nintendo Wii-Fit Plus (p < .05). Compared to single task performance in both study and control groups; it was found that the addition of a motor task impaired postural stability, while it was observed that the addition of a cognitive task only affected postural stability in the control group (p < .05).

Conclusion

Postural stability in children with SLD was found to be worse than normal children. Although the addition of concurrent motor task with postural control disrupted postural stability in both normal and SLD children, it was determined that the effect of dual task was more significant in children with SLD. While the addition of cognitive task did not affect the postural stability of children with SLD, the postural stability of normal children was observed to be affected. While performing postural control evaluations of children with SLD, not only posture task but also cognitive and motor dual task performances should be evaluated.
Newtonian calibrator tests during the Virgo O3 data taking
Authors: Estevez D , Mours B , Pradier T
Published: February 2021

The gravitational-wave detectors outputs from the LIGO and Virgo collaborations have been a source of scientific results of prime importance in various domains such as astrophysics, cosmology or fundamental physics. With the upgrades of the detectors and their improved sensitivities, new challenges are set for these instruments calibration. A calibration method based on the local variations of the Newtonian gravitational field could be the next absolute reference of calibration for the interferometers network. We report new tests of Newtonian calibrators (NCal) on the advanced Virgo detector performed during the LIGO–Virgo observing run O3. The NCal-induced strain on a mirror of the interferometer has been computed both using analytical calculations and numerical simulations with results in very good agreement. The strains given by the numerical model have been used to analyse the data of the NCals and have been compared to the reference method of calibration using photon radiation pressure. New methods to measure the NCal to mirror distance and the NCal offset with respect to the plane of the interferometer using two NCals are also presented. They are used to correct the NCal data which improves the agreement with the current advanced Virgo reference of calibration.
The Advanced Virgo photon calibrators
Authors: Estevez D , Lagabbe P , Masserot A , Rolland L , Seglar-Arroyo M , Verkindt D
Published: February 2021

As the sensitivities of LIGO, Virgo and KAGRA detectors improve, calibration of the interferometers (ITFs) output is becoming more and more important and may impact scientific results. For the observing run O3, Virgo used for the first time photon calibrators (PCals) to calibrate the ITF, using radiation pressure of a modulated auxiliary laser beam impinging on the Advanced Virgo end mirrors. Those optical devices, also used in LIGO, are now the calibration reference for the global gravitational wave detectors network. The intercalibration of LIGO and Virgo PCals, based on the same absolute reference called the gold standard, has allowed to remove a systematic bias of 3.92% that would have been present in Virgo calibration using the PCal. The uncertainty budget on the PCal-induced displacement of the end mirrors [North end (NE) and West end (WE)] of Advanced Virgo has been estimated to be 1.36% for O3a and 1.40% on NE PCal (resp. 1.74% on WE PCal) for O3b. This uncertainty is the limiting one for the global calibration of Advanced Virgo. It is expected to be reduced below ∼1% for the next observing runs.
On quantum determinants in integrable quantum gravity
Authors: Runov B
Published: February 2021

Einstein–Rosen waves with two polarizations are cylindrically symmetric solutions to vacuum Einstein equations. Einstein equations in this case reduce to an integrable system. In 1971, Geroch has shown that this system admits an infinite-dimensional group of symmetry transformations known as the Geroch group. The phase space of this system can be parametrized by a matrix-valued function of spectral parameter, called monodromy matrix. The latter admits the Riemann–Hilbert factorization into a pair of transition matrices, i.e. matrix-valued functions of spectral parameter such that one of them is holomorphic in the upper half-plane, and the other is holomorphic in the lower half-plane. The classical Geroch group preserves the determinants of transition and monodromy matrices by construction. The algebraic quantization of the quadratic Poisson algebra generated by transition matrices of Einstein–Rosen system was proposed by Korotkin and Samtleben in 1997. Paternain, Peraza and Reisenberger have recently suggested a quantization of the Geroch group, which can be considered as a symmetry of the quantum algebra of observables. They have shown that commutation relations involving quantum monodromy matrices are preserved by the action of the quantum Geroch group. In present paper we introduce the notion of the determinant of the quantum monodromy matrix. We derive a factorization formula expressing the quantum determinant of the monodromy matrix as a product of the quantum determinants of the transition matrices. The action of the quantum Geroch group is extended from the subalgebra generated by the monodromy matrixonto the full algebra of observables. This extension is used to prove that the quantum determinant of the quantum monodromy matrix is invariant under the action of quantum Geroch group.
Matching conditions in locally rotationally symmetric spacetimes and radiating stars
Authors: Khambule Pretty N , Goswami Rituparno , Maharaj Sunil D
Published: February 2021

We recast the well known Israel–Darmois matching conditions for locally rotationally symmetric (LRS-II) spacetimes using the semitetrad 1 + 1 + 2 covariant formalism. This demonstrates how the geometrical quantities including the volume expansion, spacetime shear, acceleration and Weyl curvature of two different spacetimes are related at a general matching surface inheriting the symmetry, which can be timelike or spacelike. The approach is purely geometrical and depends on matching the Gaussian curvature of two-dimensional sheets at the matching hypersurface. This also provides the constraints on the thermodynamic quantities on each spacetime so that they can be matched smoothly across the surface. As an example we regain the Santos boundary conditions and model of a radiating star matched to a Vaidya exterior in general relativity.
Structural and optical properties of self-assembled AlN nanowires grown on SiO2/Si substrates by molecular beam epitaxy
Authors: Gačević Ž , Grandal J , Guo Q , Kirste R , Varela M , Sitar Z , Sánchez García M A
Published: February 2021

Self-assembled AlN nanowires (NWs) are grown by plasma-assisted molecular beam epitaxy (PAMBE) on SiO2/Si (111) substrates. Using a combination of in situ reflective high energy electron diffraction and ex situ x-ray diffraction (XRD), we show that the NWs grow nearly strain-free, preferentially perpendicular to the amorphous SiO2 interlayer and without epitaxial relationship to Si(111) substrate, as expected. Scanning electron microscopy investigation reveals significant NWs coalescence, which results in their progressively increasing diameter and formation of columnar structures with non-hexagonal cross-section. Making use of scanning transmission electron microscopy (STEM), the NWs initial diameters are found in the 20–30 nm range. In addition, the formation of a thin (≈30 nm) polycrystalline AlN layer is observed on the substrate surface. Regarding the structural quality of the AlN NWs, STEM measurements reveal the formation of extended columnar regions, which grow with a virtually perfect metal-polarity wurtzite arrangement and with extended defects only sporadically observed. Combination of STEM and electron energy loss spectroscopy reveals the formation of continuous aluminum oxide (1–2 nm) on the NW surface. Low temperature photoluminescence measurements reveal a single near-band-edge (NBE) emission peak, positioned at 6.03 eV (at 2 K), a value consistent with nearly zero NW strain evidenced by XRD and in agreement with the values obtained on AlN bulk layers synthesized by other growth techniques. The significant full-width-at-half-maximum of NBE emission, found at ≈20 meV (at 2 K), suggests that free and bound excitons are mixed together within this single emission band. Finally, the optical properties of the hereby reported AlN NWs grown by PAMBE are comprehensively compared to optical properties of bulk, epitaxial and/or columnar AlN grown by various techniques such as: physical vapor transport, metal organic vapor phase epitaxy, metal organic chemical vapor deposition and molecular beam epitaxy.
Physicochemical defect guided dewetting of ultrathin films to fabricate nanoscale patterns
Authors: Das Abhijna , Bolleddu Ravi , Singh Amit Kumar , Bandyopadhyay Dipankar
Published: February 2021

Pathways to fabricate self-organized nanostructures have been identified exploiting the instabilities of ultrathin (<100 nm) polystyrene (PS) film on the polydimethylsiloxane (PDMS) substrates loaded with discrete and closely packed gold nanoparticles (AuNPs). The AuNPs were deposited on the PDMS substrates by chemical treatment, and the size and periodicity of the AuNPs were varied before coating the PS films. The study unveils that the physicochemical heterogeneity created by the AuNPs on the PDMS surface could guide the hole-formation, influence the average spacing between the holes formed at the initial dewetting stage, and affects the spacing and periodicity of the droplets formed at the end of the dewetting phase. The size and spacing of the holes and the droplets could be tuned by varying the nanoparticle loading on the PDMS substrate. Interestingly, as compared to the dewetting of PS films on the homogeneous PDMS surfaces, the AuNP guided dewetted patterns show ten-fold miniaturization, leading to the formation of the micro-holes and nanodroplets. The spacing between the droplets could also see a ten-fold reduction resulting in high-density random patterns on the PDMS substrate. Further, the use of a physicochemical substrate with varying density of physicochemical heterogeneities could impose a long-range order to the dewetted patterns to develop a gradient surface. The reported results can be of significance in the fabrication of high-density nanostructures exploiting the self-organized instabilities of thin polymers films.
SnO
x
/graphene anode material with multiple oxidation states for high-performance Li-ion batteries
Authors: Zhang Wenlan , Zheng Maojun , Li Fanggang , You Yuxiu , Jiang Dongkai , Yuan Hao , Ma Li , Shen Wenzhong
Published: February 2021

Tin and its oxides are promising anode materials owing to their high theoretical capacity, rich resource, and environmental benignity. To achieve low cost and green synthesis, a facile synthetic route of SnO
x
/graphene composites is proposed, using a simple galvanic replacement method to quickly obtain abundant foamed tin as raw material and ball milling method to realize a mechanochemical reaction between SnO
x
(0 ≤ x ≤ 2) and graphene. Under different annealing conditions, the foamed tin is converted to tin oxides with multiple oxidation states (Sn3O4, SnO, and SnO2). These unique components can greatly affect the electrochemical performance of the electrode in LIBs. The as-prepared electrode (SnO
x
-300/G) obtained by annealing foamed tin at 300 °C for 4 h and combining SnO
x
powders with graphene via ball milling shows great cycling stability, retaining a high capacity of 786 mA h g−1 at 0.1 A g−1 after 150 cycles, and its initial Coulombic efficiency can reach 84.03%. Thus, this facile synthesis can provide an environmentally friendly route for commercial production of high-performance energy storage materials.
Balanced strength-toughness, thermal conductivity and self-cleaning properties of PMMA composites enabled by terpolymer grafted carbon nanotube
Authors: Song Shiqiang , Li Qinglan , Zhang Cuifen , Liu Zijin , Fan Xin , Zhang Yong
Published: February 2021

Achieving a balanced strength-toughness in polymer composites is a challenge largely because of poor interfacial interaction between the fillers and matrix. Here, we report that terpolymer grafted multi-wall carbon nanotubes (Ter-CNT) imparted good dispersion of CNT in matrix and strong CNT-matrix interaction. With the addition of 2 vol% filler into polymethyl methacrylate (PMMA) matrix, the composite exhibited simultaneously a balanced strength-toughness property with flexural strength of 72.3 MPa, toughness of 10.1 MJ m−3, which increased by 40.1% and 578% compared with those of pure PMMA. In addition, the composite also shows a high static contact angle (110.3°), and thermal conductivity (0.50 Wm K−1), which endow the composite with good self-cleaning and thermal management capabilities. Thus, this preparation process shows guidance for the design of polymer composite with integrated high strength-toughness, thermal conductivity and good self-cleaning.
Ultrafast scattering dynamics of coherent phonons in Bi1−x
Sb
x
in the Weyl semimetal phase
Authors: Komori Yuta , Saito Yuta , Fons Paul , Hase Muneaki
Published: February 2021

We investigate ultrafast phonon dynamics in the Bi1−x
Sb
x
alloy system for various compositions x using a reflective femtosecond pump-probe technique. The coherent optical phonons corresponding to the A1g
local vibrational modes of Bi–Bi, Bi–Sb, and Sb–Sb are generated and observed in the time domain with a few picoseconds dephasing time. The frequencies of the coherent optical phonons were found to change as the Sb composition x was varied, and more importantly, the relaxation time of those phonon modes was dramatically reduced for x values in the range 0.5–0.8. We argue that the phonon relaxation dynamics are not simply governed by alloy scattering, but are significantly modified by anharmonic phonon–phonon scattering with implied minor contributions from electron–phonon scattering in a Weyl-semimetal phase.
Significance of Reynolds number, lower and upper rotating disks on the dynamics of water conveying graphene and silver nanoparticles between rotating disks
Authors: Mahesh A , Varma S V K , Raju C S K , Jayachandra Babu M , Animasaun I L , Shah Nehad Ali
Published: February 2021

Despite numerous reports on the newly discovered hybrid nanofluid, little is known on the influence of increasing Reynolds number, stretching of lower, and upper disks on the dynamics of water conveying graphene and silver between rotating disks when Lorentz force, Joule heating, suction, thermal radiation of thermal energy, and Cattaneo-Christov heat flux are highly significant. This report provides insight into such transport phenomenon with an emphasis on the increasing effects of Reynolds number, stretching of lower, and upper disks. Initially, leading equations of motion and energy are transmuted into a system of nonlinear ordinary differential equations with the aid of suitable (Von-Karman) similarity transmutations. Later, by enforcing shooting procedure (R-K 4th order based) to obtain the numerical solutions. Based on the analysis, it is worth concluding that increasing the Reynolds number improves the thermal field but reduces the tangential velocity. Entropy generation is an increasing property of stretching lower and upper disks but these are yardsticks for decreasing Bejan number.
J—state solutions and thermodynamic properties of the Tietz oscillator
Authors: Eyube E S , Yerima J B , Ahmed A D
Published: February 2021

In this work, we have solved the radial part of the Schrödinger equation with Tietz potential to obtain explicit expressions for bound state ro-vibrational energies and radial eigenfunctions. The proper quantization rule and ansatz solution technique were used to arrive at the solutions. In modeling the pseudo-spin–orbit term of the effective potential, the Pekeris-like and the Greene-Aldrich approximation recipes were applied. Using our equation for eigen energies, we have deduced expression for bound state energy eigenvalues of Deng-Fan oscillator. The result obtained agrees with available literature data for this potential. Also, for arbitrary values of rotational and vibrational quantum numbers, we have calculated bound state energies for the Tietz oscillator. Our computed results are in excellent agreement with those in the literature. Furthermore, the result showed that unlike Greene-Aldrich approximation, energies computed based on Pekeris-like approximation are better and almost indistinguishable from numerically obtained energies of the Tietz oscillator in the literature. With the help of our formula for ro-vibrational energy, analytical expressions for some important thermodynamic relations were also derived for the Tietz oscillator. The derived thermal functions which include ro-vibrational: partition function, free energy, mean energy, entropy and specific heat capacity were subsequently applied to the spectroscopic data of KI diatomic molecule. Studies of the thermal functions indicated that the partition function decreases monotonically as the temperature is raised and increases linearly for increase in the upper bound vibrational quantum number. On the other hand, increase in either temperature or upper bound vibrational quantum number amounts to monotonic rise in the entropy of the KI molecules
Extended-source broken gate tunnel FET for improving direct current and analog/radio-frequency performance*
Authors: Xu Hui-Fang , Sun Wen , Wang Na
Published: February 2021

The various advantages of extended-source (ES), broken gate (BG), and hetero-gate-dielectric (HGD) technology are blended together for the proposed tunnel field-effect transistor (ESBG TFET) in order to enhance the direct-current and analog/radio-frequency performance. The source of the ESBG TFET is extended into channel for the purpose of increasing the point and line tunneling in the device at the tunneling junction, and then, the on-state current for the ESBG TFET increases. The influence of the source region length on the direct-current and radio-frequency performance parameters of the ESBG TFET is analyzed in detail. The results show that the proposed TFET exhibits a high on-state current to off-state current ratio of 1013, large transconductance of 1200 μS/μm, high cut-off frequency of 72.8 GHz, and high gain bandwidth product of 14.3 GHz. Apart from these parameters, the ESBG TFET also demonstrates high linearity distortion parameters in terms of the second- and third-order voltage intercept points, the third-order input interception point, and the third-order intermodulation distortion. Therefore, the ESBG TFET greatly promotes the application potential of conventional TFETs.
Reduction of PDF uncertainty in the measurement of the weak mixing angle at the ATLAS experiment *
Authors: Fu Yao , Yang Siqi , Liu Minghui , Han Liang , Hou Tie-Jiun , Schmidt Carl , Wang Chen , Yuan C.-P.
Published: February 2021

We investigate the parton distribution function (PDF) uncertainty in the measurement of the effective weak mixing angle

at the CERN Large Hadron Collider (LHC). The PDF-induced uncertainty is large in proton-proton collisions at the LHC due to the dilution effect. The measurement of the Drell-Yan forward-backward asymmetry (

) at the LHC can be used to reduce the PDF uncertainty in the

measurement. However, when including the full mass range of lepton pairs in the

data analysis, the correlation between the PDF updating procedure and the

extraction leads to a sizable bias in the obtained

value. From our studies, we find that the bias can be significantly reduced by removing Drell-Yan events with invariant mass around the Z-pole region, while most of the sensitivity in reducing the PDF uncertainty remains. Furthermore, the lepton charge asymmetry in the W boson events as a function of the rapidity of the charged leptons,

, is known to be another observable which can be used to reduce the PDF uncertainty in the

measurement. The constraint from

is complementary to that from

, and thus no bias affects the

extraction. The studies are performed using the error PDF Updating Method Package (ePump), which is based on Hessian updating methods. In this article, the CT14HERA2 PDF set is used as an example.
Wrist-driven passive grasping: interaction-based trajectory adaption with a compliant anthropomorphic hand
Authors: Gilday Kieran , Hughes Josie , Iida Fumiya
Published: February 2021

The structure of the human musculo-skeletal systems shows complex passive dynamic properties, critical for adaptive grasping and motions. Through wrist and arm actuation, these passive dynamic properties can be exploited to achieve nuanced and diverse environment interactions. We have developed a passive anthropomorphic robot hand that shows complex passive dynamics. We require arm/wrist control with the ability to exploit these. Due to the soft hand structures and high degrees of freedom during passive-object interactions, bespoke generation of wrist trajectories is challenging. We propose a new approach, which takes existing wrist trajectories and adapts them to changes in the environment, through analysis and classification of the interactions. By analysing the interactions between the passive hand and object, the required wrist motions to achieve them can be mapped back to control of the hand. This allows the creation of trajectories which are parameterized by object size or task. This approach shows up to 86% improvement in grasping success rate with a passive hand for object size changes up to ±50%.
A health impact assessment of long-term exposure to particulate air pollution in Thailand
Authors: Mueller William , Vardoulakis Sotiris , Steinle Susanne , Loh Miranda , Johnston Helinor J , Precha Nopadol , Kliengchuay Wissanupong , Sahanavin Narut , Nakhapakorn Kanchana , Sillaparassamee Ratthapol , Tantrakarnapa Kraichat , Cherrie John W
Published: February 2021

Particulate air pollution causes a spectrum of adverse health effects affecting the respiratory, cardiovascular, neurological, and metabolic systems that are hypothesised to be driven by inflammation and oxidative stress. Millions of premature deaths each year are attributed to exposure to ambient particulate matter (PM). We quantified health and economic impacts from long-term exposure to ambient PM2.5 in the population of Thailand for 2016. We collected data on ambient PM2.5 concentrations from automatic monitoring stations across Thailand over 1996–2016. We used historic exposure to PM2.5 to estimate the mortality in each province from lower respiratory infections (LRIs), stroke, chronic obstructive pulmonary disease, lung cancer, and ischaemic heart disease, and also assessed diabetes mortality, as well as incident cases of dementia and Parkinson’s disease, in supplementary analyses. We applied risk estimates from the Global Exposure Mortality Model to calculate attributable mortality and quantify disability-adjusted life years (DALYs); we based economic costs on the value of a statistical life (VSL). We calculated 50 019 (95% confidence interval [CI]: 42 189–57 849) deaths and 508 918 (95% CI: 438 345–579 492) DALYs in 2016 attributed to long-term PM2.5 exposure in Thailand. Population attributable fractions ranged from 20% (95% CI: 10% to 29%) for stroke to 48% (95% CI: 27% to 63%) for LRIs. Based on the VSL, we calculated a cost of US$ 60.9 billion (95% CI: US$ 51.3–70.4 billion), which represents nearly 15% of Thailand’s gross domestic product in 2016. While progress has been made to reduce exposure to ambient PM2.5 in Thailand, continued reductions based on stricter regulatory limits for PM2.5 and other air pollutants would help prolong life, and delay, or prevent, onset of cardiorespiratory and other diseases.
Correlation Analysis of Indoor and Outdoor PM2.5 and Exploration of Prevention Methods
Authors: Pan Hui , Wang Hongyun , Qian Yong , Tang Yan
Published: February 2021

In order to study the correlation of indoor and outdoor PM2.5 concentrations, five sampling points are selected in Hunnan New District of Shenyang City. The PM2.5 concentration inside and outside the five buildings were monitored in December 2018. After that, the writers analyze the variation characteristics and trends, and explore the prevention and control methods to indoor and outdoor PM2.5. The results show that there is a significant correlation between indoor and outdoor PM2.5 concentration, and the concentration is affected by opening or closing windows. When there is no indoor pollution source, indoor pollutants mainly come from outdoor infiltration. The prevention and control of PM2.5 pollution can be divided into indoor and outdoor aspects. Scholars often ignore the harm of PM2.5 to human body when they stay in the house. In indoor environment, PM2.5 is analyzed through aerodynamics. Due to the slow air flow, the inhalation volume of human body is more than that in the outdoor environment with fast air flow. In this paper, we will discuss how to reduce the harm of PM2.5 to human body and create a healthy living environment for residents.
Research on adaptive ship trim energy saving scheme based on intelligent loading
Authors: Gao Yibo
Published: February 2021

The system is a set of control system based on ship trimming energy-saving designed through deep learning algorithm, particle swarm algorithm and data optimization. Through the deep learning algorithm, the collected data is deep learning, the result of intelligent learning is used as the objective function, and the particle swarm algorithm combined with the loading software is used to adjust the loading state, sail with a fixed inclination angle and collect this fixed inclination angle during the voyage. A certain range of nearby data is systematically revised to make the system more perfect. Finally, a universal method can be obtained, which can be applied to different types of ships, and the corresponding trim optimization suggestions will be given to the complicated factors encountered in the navigation process.