bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of custom‐fitted compression garments worn overnight for recovery from judo training in elite athletes
Authors: Brown Freddy C.W. , Hill Jessica A. , van Someren Ken , Howatson Glyn , Pedlar Charles R. 
Published: February 2021

ABSTRACTThis study investigated the effects of custom‐fitted compression garments (CG) worn during recovery over a multi‐day training camp in elite judo players (judoka). A single blind, placebo‐controlled study was carried out in 11 elite judoka, using a two‐way crossover design. Two three‐day training camps were completed in CG and placebo conditions in a random order. Changes in performance and physiological markers were compared between conditions. Judoka were assessed before training for (maximal) isometric knee extension and grip strength, countermovement jump performance and bench‐press velocity, alongside soreness, limb circumferences, plasma creatine kinase activity (CK) and perceived bruising. Measurements were repeated after 12, 36 and 43 h of training, whereupon judoka rated the effectiveness of each intervention. Knee extension and bench‐press performance demonstrated significant familiarization (p < 0.001), and were excluded from subsequent analysis. Jump performance was unaffected by training (p > 0.05). Grip strength declined throughout training (p < 0.001), with peak decrements of −9.7% indicating mild muscle damage. Increases in bruising, CK and soreness demonstrated highly variable, if significant (p < 0.001) responses. Although CG were perceived as significantly more effective than placebo for recovery (p = 0.046), no effects were observed for any other outcome (p > 0.05). Compression conferred no statistically significant impact upon recovery markers in elite judoka throughout training. Muscle damage responses were inconsistent in this population. Individual athletes would be advised to monitor habitually‐used performance measures while using CG to ascertain whether perceptual benefits translate into enhanced recovery.Highlights
Compression garments were perceived as more effective for recovery than placebo by elite judoka.
However, no measures of performance or muscle damage were enhanced by CG.
Randori was associated with inconsistent muscle damage responses in elite judoka, while lower‐body performance was not impaired.
Individual athletes would be advised to monitor habitually‐used performance measures while using CG to ascertain whether perceptual benefits translate into enhanced recovery.
On the quasi-position representation in theories with a minimal length
Authors: Bosso Pasquale 
Published: February 2021

Abstract
Quantum mechanical models with a minimal length are often described by modifying the commutation relation between position and momentum. Although this represents a small complication when described in momentum space, at least formally, the (quasi-)position representation acquires numerous issues, source of misunderstandings. In this work, we review these issues, clarifying some of the aspects of minimal length models, with particular reference to the representation of the position operator.
The pedagogical representation of mass functions with LEGO and their origin
Authors: Kautsch Stefan J , Veras Dimitri , Hansotia Kyle K 
Published: February 2021

Abstract
We promote the teaching of mass functions as an integral part of an interdisciplinary science education. Mass functions characterize the frequency distributions of objects with different masses on all cosmic scales. We intend to enhance experiential learning of this concept with a creative LEGO brick experiment for a diverse student audience. To our surprise, the LEGO mass function is not only qualitatively but also quantitatively comparable to mass functions found across the Universe. We also discuss the relation between gravitation and mass distributions as a possible explanation for the continuity of the universal mass function.
Sacrificial grid release technology: a versatile release concept for MEMS structures
Authors: Zhao Y , Janssens Y L , Veltkamp H-W , de Boer M J , Groenesteijn J , Tas N R , Wiegerink R J , Lötters J C 
Published: February 2021

Abstract
Micro-electro-mechanical-systems (MEMS) structures with different in-plane dimensions often need to be released simultaneously from the bulk of the wafer and a single dry etching or wet etching technique cannot fulfill all release requirements. In this paper we present a universally applicable solution to release MEMS structures with different surface areas in a controlled and uniform way, which combines isotropic etching of a sacrificial silicon support structure by xenon difluoride with a predefined etch surface made by deep reactive ion etching. Two applications of this Sacrificial Grid Release Technology are presented, in which MEMS devices are released in silicon-on-insulator wafers. The demonstrated applications involve the release of microstructures with in-plane dimensions ranging from tens of micrometers to a few millimeters. The sacrificial silicon structure provides mechanical support which allows freedom in process flow design for fragile MEMS structures. The release technique can also be used to separate the chips from the wafer.
Experimental investigation of ignition by multichannel gliding arcs in a swirl combustor
Authors: Lin Dong , Jia Min , Zhang Zhibo , Song Huimin , Cui Wei , Wang Weizhen , Cai Banghuang 
Published: February 2021

Abstract
In the extreme conditions of high altitude, low temperature, low pressure and high speed, the aircraft engine has a strong tendency to extinguish and it is then difficult to start secondary ignition, which means that re-ignition of the aircraft engine faces great challenges. Additionally, the ability of the single-channel gliding arc (1-GA) in assisting the ignition under extreme conditions is weak. In this paper, to solve this problem, a multichannel gliding arcs (MGA) system is proposed, using the principle of multichannel discharge. Experiments on the electrical characteristics and ignition performance of MGA were conducted under atmospheric pressure in a swirl model combustor. The electrical characteristics of MGA were investigated under different air velocities. The ignition process of MGA was recorded by using a high-speed camera with CH* filter. Results show that the three-channel gliding arcs (3-GA) and five-channel gliding arcs (5-GA) generated more averaged power than the 1-GA under a constant air velocity. For example, the 3-GA and 5-GA generated 112.8% and 187.3% more averaged power than that of the 1-GA at 74.6 m s−1, respectively. The arc shapes of gliding arcs with different channel numbers were different and the duration time of ‘breakdown-stretching-extinguishing’ of MGA shortened. Furthermore, compared with the 1-GA, the percentage of the lean ignition limit widening of the 3-GA and 5-GA can reach 13.5% and 20.9% respectively. The frequency of re-breakdown in the discharge process using different gliding arc channel numbers is different, which can continuously inject energy into the combustor and generate the ‘flame combination’ phenomenon producing a larger flame area. The ignition process of MGA can be divided into three stages: sliding stage, flame combination stage and flame stabilization stage.
VSe2 quantum dots with high-density active edges for flexible efficient hydrogen evolution reaction
Authors: Wang Chaolun , Jin Mengge , Liu Dongming , Liang Fang , Luo Chen , Li Panlin , Cai Chunhua , Bi Hengchang , Wu Xing , Di Zengfeng 
Published: February 2021

Abstract
Two-dimensional (2D) metallic transition metal dichalcogenides (TMDCs) with large specific surface areas and high conductivities are promising catalysts for electrocatalytic hydrogen production. The highly active edges of the 2D metallic TMDCs are the desirable catalytic sites for the hydrogen evolution reaction (HER). Herein, the vanadium diselenide (VSe2) quantum dots with high-density edge sites are prepared by tip sonication of the self-detached VSe2 nanosheets. The spontaneously released VSe2 nanosheets, without chemical-involved transfer, offer a noncontaminated catalyst for HER. Compared to the VSe2 nanosheets, VSe2 quantum dots with a high density of active edges present a significant enhancement of the electrocatalytic performance. The reduced overpotential and transfer resistance indicate the lower Gibbs free energy and faster faradic process of the VSe2 quantum dots for HER. The active edge sites of VSe2 quantum dots show improved catalytic properties in thermodynamic and kinetic aspects. The VSe2 quantum dots loaded on a carbon cloth could be used as a flexible electrode for HER. This work provides an effective way to regulate the defects of the 2D TMDCs for high-performance HER catalysts and also offers a catalyst for flexible HER.
Charge. transport, conductivity and Seebeck coefficient in pristine and TCNQ loaded preferentially grown metal-organic framework films
Authors: Chen Xin , Zhang Kai , Hassan Zeinab Mohamed , Redel Engelbert , Baumgart Helmut 
Published: February 2021

Abstract
This investigation on metal-organic framework (MOF) HUKUST-1 films focuses on comparing the undoped pristine state and with the case of doping by TCNQ infiltration of the MOF pore structure. We have determined the temperature dependent charge transport and p-type conductivity for HKUST-1 films. Furthermore, the electrical conductivity and the current–voltage characteristics have been characterized in detail. Because the most common forms of MOFs, bulk MOF powders, do not lend themselves easily to electrical characterization investigations, here in this study the electrical measurements were performed on dense, compact surface-anchored metal-organic framework (SURMOF) films. These monolithic, well-defined, and (001) preferentially oriented MOF thin films are grown using quasi-liquid phase epitaxy (LPE) on specially functionalized silicon or borosilicate glass substrates. In addition to the pristine SURMOF films also the effect of loading these porous thin films with TCNQ has been investigated. Positive charge carrier conduction and a strong anisotropy in electrical conduction was observed for highly oriented SURMOF films and corroborated with Seebeck coefficient measurements. Van der Pauw four-point Hall sample measurements provide important insight into the electrical behavior of such porous and hybrid organic–inorganic crystalline materials, which renders them attractive for potential use in microelectronic and optoelectronic devices and thermoelectric applications.
General theory of electroadhesion
Authors: Persson Bo N J 
Published: February 2021

Abstract
We present a general theory of electroadhesion assuming layered materials with finite electric conductivity and an air gap resulting from interfacial surface roughness. The theory reduces to the results derived in Persson (2018 J. Chem. Phys.
148 144701) in the appropriate limits. We present numerical results to illustrate the theory.
Detection of impact on aircraft composite structure using machine learning techniques
Authors: Ai Li , Soltangharaei Vafa , Bayat Mahmoud , Van Tooren Michel , Ziehl Paul 
Published: February 2021

Abstract
Aircraft structures are exposed to impact damage caused by debris and hail during their service life. One of the design concerns in composite structures is the resistance of layered surfaces to damage, which occurs from impacts with various foreign objects. Therefore, the impact localization and damage quantification of impacts should be studied and considered to address flight safety and to reduce costs associated with a regularly scheduled visual inspection. Since the structural components of the aircraft are large scale, visual inspection and monitoring are challenging and subject to human error. This paper presents a promising solution that can automatically detect and localize an impact that may occur during flight. To achieve this goal, acoustic emission (AE) is employed as an impact monitoring approach. Random forest and deep learning were adopted for training the source location models. An AE dataset was collected by conducting an impact experiment on a full-size thermoplastic aircraft elevator in a laboratory environment. A dataset consisting of AE parametric features and a dataset consisting of AE waveforms were assigned to a random forest classifier and deep learning network for the investigation of their applicability of impact source localization. The results obtained were compared using the source localization approach in previous research using a conventional artificial neural network. The analysis of results shows the random forest and deep learning leads to better event localization performance. In addition, the random forest model can provide the importance of features. By deleting the least important features, the storage required to save the input and the computing time for the random forest is greatly reduced, and an acceptable localization performance can still be obtained.
Nanoindentation of mesenchymal stem cells using atomic force microscopy: effect of adhesive cell-substrate structures
Authors: Migliorini Elisa , Cavalcanti-Adam Elisabetta Ada , Uva Antonio Emmanuele , Fiorentino Michele , Gattullo Michele , Manghisi Vito Modesto , Vaiani Lorenzo , Boccaccio Antonio 
Published: February 2021

Abstract
The procedure commonly adopted to characterize cell materials using atomic force microscopy neglects the stress state induced in the cell by the adhesion structures that anchor it to the substrate. In several studies, the cell is considered as made from a single material and no specific information is provided regarding the mechanical properties of subcellular components. Here we present an optimization algorithm to determine separately the material properties of subcellular components of mesenchymal stem cells subjected to nanoindentation measurements. We assess how these properties change if the adhesion structures at the cell-substrate interface are considered or not in the algorithm. In particular, among the adhesion structures, the focal adhesions and the stress fibers were simulated. We found that neglecting the adhesion structures leads to underestimate the cell mechanical properties thus making errors up to 15%. This result leads us to conclude that the action of adhesion structures should be taken into account in nanoindentation measurements especially for cells that include a large number of adhesions to the substrate.
Novel 2D B2S3 as a metal-free photocatalyst for water splitting
Authors: Li Xiaoteng , Cui Bin , Zhao Wenkai , Xu Yuqing , Zou Dongqing , Yang Chuanlu 
Published: February 2021

Abstract
Metal-free semiconductors with desirable characteristics have recently gained great attention in the field of hydrogen generation. The non-metal material B2S3 has two phases, hexagonal B2S3 (h-B2S3) and orthorhombic B2S3 (o-B2S3), which compose a novel class of 2D materials. Both h-B2S3 and o-B2S3 monolayers are direct semiconductors with bandgaps of 2.89 and 3.77 eV by the Heyd-Scuserria-Ernzerhof (HSE) function, respectively. Under appropriate uniaxial strain (1%), the bandgap of h-B2S3 can be decreased to 2.8 eV. The carrier mobility can reach 1160 cm2 V−1 s−1, supporting the fast migration of photo-induced carriers. Most importantly, the band edges of both h-B2S3 and o-B2S3 cover the reduction and oxidation levels for water splitting. We explore the process of photocatalytic water splitting on h-B2S3 monolayers by analyzing the feasibility of the decomposition of H2O and the generation of H2. The results indicate that the special mesoporous structure of B2S3 is helpful for photocatalytic hydrogen production. The new nanomaterial, B2S3, offers great promise as a metal-free photocatalyst due to its tunable bandgaps, its useful band edges, and its other excellent electronic properties.
Proposal of graphene band-gap enhancement via heterostructure of graphene with boron nitride in vertical stacking scheme
Authors: Sattar Abdul , Moazzam Uzair , Bashir Azmat Iqbal , Reza Ali , Latif Hamid , Usman Arslan , Amjad Raja Junaid , Mubshrah Ayesha , Nasir Abdullah 
Published: February 2021

Abstract
Since the discovery of graphene and other two-dimensional (2D) materials in recent years, heterostructures composed of multilayered 2D materials have attracted immense research interest. This is mainly due to the potential prospects of the heterostructures for basic and applied applications related to the emerging technology of energy-efficient optoelectronic devices. In particular, heterostructures of graphene with 2D materials of similar structure have been proposed to open up the band gap to tune the transport properties of graphene for a variety of technological applications. In this paper, we propose a heterostructure scheme of band-gap engineering and modification of the electronic band structure of graphene via the heterostructure of graphene–boron nitride (GBN) based on first-principles calculations. For a comparative analysis of the properties of the proposed GBN heterostructure, we employ Kohn–Sham density functional theory (DFT) using local density and generalized gradient approximations within Perdew–Burke–Ernzehof parameterization. To account for weak interlayer van der Waals interactions, we employ the semi-empirical dispersion-corrected DFT scheme of Grimme, called the DFT-D2 approximation. In the vertical stacking arrangement of boron-nitride-doped graphene with hexagonal boron nitride, we predict a band-gap opening of 1.12 eV which, to our knowledge, is the largest value attained for this kind of system. The impact of interlayer spacing on the band-gap opening arising from the interlayer coupling effect is also analyzed. The band-gap enhancement supports the widely proposed promise of GBN heterostructure in design of high-performance optoelectronic devices such as field-effect transistors for potential applications.
Synthetic dual-energy CT for MRI-only based proton therapy treatment planning using label-GAN
Authors: Liu Ruirui , Lei Yang , Wang Tonghe , Zhou Jun , Roper Justin , Lin Liyong , McDonald Mark W , Bradley Jeffrey D , Curran Walter J , Liu Tian , Yang Xiaofeng 
Published: February 2021

Abstract
MRI-only treatment planning is highly desirable in the current proton radiation therapy workflow due to its appealing advantages such as bypassing MR-CT co-registration, avoiding x-ray CT exposure dose and reduced medical cost. However, MRI alone cannot provide stopping power ratio (SPR) information for dose calculations. Given that dual energy CT (DECT) can estimate SPR with higher accuracy than conventional single energy CT, we propose a deep learning-based method in this study to generate synthetic DECT (sDECT) from MRI to calculate SPR. Since the contrast difference between high-energy and low-energy CT (LECT) is important, and in order to accurately model this difference, we propose a novel label generative adversarial network-based model which can not only discriminate the realism of sDECT but also differentiate high-energy CT (HECT) and LECT from DECT. A cohort of 57 head-and-neck cancer patients with DECT and MRI pairs were used to validate the performance of the proposed framework. The results of sDECT and its derived SPR maps were compared with clinical DECT and the corresponding SPR, respectively. The mean absolute error for synthetic LECT and HECT were 79.98 ± 18.11 HU and 80.15 ± 16.27 HU, respectively. The corresponding SPR maps generated from sDECT showed a normalized mean absolute error as 5.22% ± 1.23%. By comparing with the traditional Cycle GANs, our proposed method significantly improves the accuracy of sDECT. The results indicate that on our dataset, the sDECT image form MRI is close to planning DECT, and thus shows promising potential for generating SPR maps for proton therapy.
Auto-calibration of cone beam geometries from arbitrary rotating markers using a vector geometry formulation of projection matrices
Authors: Graetz Jonas 
Published: February 2021

Abstract
An efficient method for the determination of the projection geometry of cone beam micro computed tomography systems based on two or more fiducial markers of unknown position within the field of view is derived. By employing the projection matrix formalism commonly used in computer graphics, a very clear presentation of the resulting self consistent calibration problem can be given relating the sought-for matrix to observable parameters of the markers’ projections. Both an easy to implement solution procedure for both the unknown projection matrix and the marker assembly as well as the mapping from projection matrices to real space positions and orientations of source and detector relative to the rotational axis are provided. The separate treatment of the calibration problem in terms of projection matrices on the one hand and the independent transformation to a more intuitive geometry representation on the other hand proves to be very helpful with respect to the discussion of the ambiguities occurring in reference-free calibration. In particular, a link between methods based on knowledge on the sample and those based on knowledge solely on the detector geometry can be drawn. This further provides another intuitive view on the often reported difficulty in the estimation of the detector tilt towards the rotational axis. A simulation study considering 106 randomly generated cone beam imaging configurations and fiducial marker distributions within a range of typical scenarios is performed in order to assess the stability of the proposed technique. An experimental example supports the simulation results.
A thick semi-monolithic scintillator detector for clinical PET scanners
Authors: Zhang Chunhui , Wang Xiaohui , Sun Mingdao , Kuang Zhonghua , Zhang Xianming , Ren Ning , Wu San , Sang Ziru , Sun Tao , Hu Zhanli , Yang Yongfeng , Liu Zheng 
Published: February 2021

Abstract
Both monolithic and semi-monolithic scintillator positron emission tomography (PET) detectors can measure the depth of interaction with single-ended readout. Usually scintillators with a thickness of 10 mm or less are used since the position resolutions of the detectors degrade as the scintillator thickness increases. In this work, the performance of a 20 mm thick long rectangular semi-monolithic scintillator PET detector was measured by using both single-ended and dual-ended readouts with silicon photomultiplier (SiPM) arrays to provide a high detection efficiency. The semi-monolithic scintillator detector consists of nine lutetium–yttrium oxyorthosilicate slices measuring 1.37 × 51.2 × 20 mm3 with erythrocyte sedimentation rate foils of 0.065 mm thickness in between the slices. The SiPM array at each end of the scintillator detector consists of 16 × 4 SiPMs with a pixel size of 3.0 × 3.0 mm2 and a pitch of 3.2 mm. The 64 signals of each SiPM array are processed by using the TOFPET2 application-specific integrated circuit individually. All but the edge slices can be clearly resolved for the detectors with both single-ended and dual-ended readouts. The single-ended readout detector provides an average full width at half maximum (FWHM) Y (continuous direction) position resolution of 2.43 mm, Z (depth direction) position resolution of 4.77 mm, energy resolution of 25.7% and timing resolution of 779 ps. The dual-ended readout detector significantly improves the Y and Z position resolutions, slightly improves the energy and timing resolution at the cost of two photodetectors required for one detector module and provides an average FWHM Y position resolution of 1.97 mm, Z position resolution of 2.60 mm, energy resolution of 21.7% and timing resolution of 718 ps. The energy and timing resolution of the semi-monolithic scintillator detector in this work are worse than those of the segmented scintillator array detector and need to be further improved. The semi-monolithic scintillator detector described in this work reduces costs as compared to the traditional segmented scintillator array detector and reduces the edge effect as compared to the monolithic scintillator detector.