bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of artificial intelligence algorithms to monitor the technical condition of energy-intensive tractors
Authors: Kostomakhin Mikhail , Pestryakov Efim , Sayapin Alexander , Tseiko Mikhail , Kostomakhin Nikolay
Published: December 2023

The development of new software that uses artificial intelligence in its work is being carried out all over the world. Also in parallel with the programs new computing devices are being developed that allow storing and processing large amounts of data. It allows us to create complex computer systems that involve many third-party devices. This article is devoted to the growing role of artificial intelligence in agriculture, namely in diagnosing the condition of agricultural machinery. Modern devices for diagnosing the condition of the tractor fleet allow us to accumulate a large amount of information. Also on many modern tractors the manufacturer already provides a built-in on-board system based on a CAN interface, which serves to control the operation of the equipment. It allows us to accumulate huge data banks. But the question now arises about processing all this information. This article describes methods for structuring large amounts of such information and most importantly analyzing them using artificial intelligence algorithms.
Study of the movement of semi-finished products between working shafts
Authors: Bahadirov Gayrat , Musirov Makhmarajab , Nabiev Ayder , Pirnazarov Gulomjon
Published: December 2023

The article examines the movement of semi-finished products in the field of covering with rotating working shafts. As a result of the research, it was determined that in order to improve the quality of processed ore semi-finished products, it is necessary to increase the coverage angle and reduce the radius of the working shafts accordingly. In order to maintain the natural quality of the semi-finished ore product being processed, it is known and justified that if the value of the external pressure force is increased, the radii of the working shafts should also be increased accordingly.
Experimental sample for diagnosis of hydraulic drive pumps of agricultural equipment by pressure pulsation coefficient
Authors: Kostomakhin Mikhail , Petrishchev Nikolay , Sayapin Alexander , Pestryakov Efim , Tseiko Vitalii , Kostomakhin Nikolay
Published: December 2023

It is well known that often hydraulic pumps are resource-limiting components of the units in whose design they are included, and the condition of the hydraulic pump determines the performance and efficiency of the entire unit. The purpose of the work was to develop a prototype of a diagnostic tool that provides monitoring of the technical condition of hydraulic pumps during operation. An analysis of the tools produced by the Federal Scientific Agro-Engineering Center VIM for diagnosing the technical condition of hydraulic pumps of agricultural machinery was carried out. The material of research was a prototype of a tool for diagnosing the technical condition of hydraulic units, which was based on the method of amplitude-phase characteristics for rapid assessment of the technical condition of pumps during operation. On the base of our research we came to conclusions that for further development of the technology and subsequent implementation of the presented prototype in the process of diagnosing hydraulic pumps by pulsation coefficient it is necessary to increase the controllability of hydraulic systems of agricultural machinery by installing diagnostic points for connecting pressure sensors. Also together with manufacturers of hydraulic units, develop criteria for nominal, permissible, limit states, characterized by both the supply coefficient KQ and the pulsation coefficient ɛ.
Design of automated installation for soil tillage machines’ disc working elements hardening
Authors: Dobrin Dmitriy
Published: December 2023

This article is devoted to the development of an automated unit for hardening of disc working tools by plasma-powder surfacing with powder feeding from outside the plasmatron. The introduction describes the actual problems arising during the work of soil cultivation tools. The conducted analysis of literature sources allowed to determine the main methods of increasing the resource of disc working bodies, used at present, and their advantages and disadvantages are described. As one of the methods of increasing the resource of disc working tools the method of plasma-powder surfacing with vertical arrangement of plasmatron and powder feeding through the plasmatron is considered. The method of high-speed plasma-powder surfacing with powder feeding from outside the plasmatron into the zone of the highest temperatures of the plasma arc by means of a doser of the original patented design was chosen for the creation of the present installation. The control scheme of the installation elements is developed and presented in graphic form. The principle of operation of the main units and components of the installation is described. The basic questions of modularity and variability of application of installations of such class, and also prospects of their development at the enterprises of agrocomplex are disclosed. In the discussion the actual issues of labour conditions of the plant operator are touched upon. The conclusion presents the main conclusions on the work carried out and the developed plant.
The temperature of the elliptical cross section under boundary conditions of the first and third kind
Authors: Kanareykin Aleksandr
Published: December 2023

This paper provides a solution to the heat transfer problem for a hollow elliptical cylinder under boundary conditions of the first and third kind. In this paper, a solution is given for the distribution of the temperature field in a field with an elliptical cross section under boundary conditions of the third kind. The solution is obtained by considering equidistant surfaces.
Investigation of Electron Capture in 176Lu with a LYSO crystal scintillator
Authors: Nozzoli Francesco , Ghezzer Luigi Ernesto , Nicolaidis Riccardo , Iuppa Roberto , Zuccon Paolo
Published: December 2023

The nuclide 176Lu is one of the few naturally occurring isotopes that are potentially unstable with respect to electron capture (EC). Although experimental evidence for 176Lu EC decay is still missing, this isotope is instead well known to β− decay into 176Hf with an half-life of about 38 Gyr. Previous searches for the 176Lu EC decay were performed by using a passive Lutetium source coupled with an HP-Ge spectrometer. Our approach uses a LYSO crystal both as Lutetium source and as an active detector and the obtained 176Lu EC branching ratio limits are 7 × 10−4 and 4.4 × 10−4 for the capture of the 1s and 2s electron, respectively. Previously known limits for the EC in 176Lu are improved by a factor 3 to 15 depending on the considered EC channel.
Alpha emission from fast neutron interactions with 64Zn nuclei
Authors: Oprea Cristiana , Mihul Alexandru , Oprea Ioan , Gruia Ion , Zgura Sorin
Published: December 2023

In this study, the nuclear process 64Zn(n, α)61Ni induced by fast neutrons in the 64Zn nucleus was investigated. With the authors' computer programs and Talys codes, cross-sections, angular correlations, and forward-backward asymmetry effects were investigated for incident neutrons with energies ranging from 0.5 MeV to 25 MeV. 61Ni cross-sections were determined through an investigation of nuclear reaction mechanisms (direct, compound, pre-equilibrium) and discrete and continuum states within the 61Ni residual nucleus. Our analysis of the neutron incident and alpha emergent channels included the extraction of optical potential parameters (with real and imaginary parts) with volume, surface, and spin-orbit components. The cross-sections calculated theoretically and found in our experiments confirm earlier published data. For neutrons with energies of a few MeV, the 64Zn(n, α)61Ni reaction produced by fast neutrons exhibits an unusual forward-backward asymmetry. At this energy, the observed effect cannot be explained by direct mechanisms with orders of magnitude lower; compound processes that predominate must be used. To understand the observed forward-backward asymmetry effect, the spectra of emitted alpha particles were modelled by the direct Monte Carlo method while taking into consideration the energy loss of alpha particles on Zn targets with finite dimensions.
Scattering of 15C on 208Pb at energies near the Coulomb barrier: Study of the experimental device response via the 12C+208Pb scattering
Authors: Távora V.G. , Ovejas J.D. , Martel I. , Tengblad O. , Borge M.J.G. , Acosta L. , Kurtukian-Nieto T. , Sánchez-Benítez A.M. , di Pietro A. , Figuera P. , Keeley N. , Rusek K. ,   the IS619 collaboration
Published: December 2023

There are evidences that the 15C nucleus has an extended neutron distribution or a "neutron halo", but this situation is far from clear. If 15C has 1n-halo, the scattering dynamics should be affected and the angular distribution of the elastic channels should be sensitive to coupling effects due to the halo configuration. The objetive of this study is to understand the role of the halo in 15C by investigating its dynamical response in intense electric fields at energies close to the Coulomb barrier. For this purpose experiment IS619 was conducted performing the 15C + 208Pb elastic scattering reaction at HIE-ISOLDE, CERN. The beam energy was 4.37 MeV/u, which is very close to the Coulomb barrier of the system. The experimental setup used was the global detection system GLORIA, a six silicon telescopes array enable to measure the energy and angular distributions of the scattered particles. During the experiment, the 12C+208Pb scattering at 4.37 MeV/u was measured for calibration. The results of the 12C+208Pb measurement were used to fine-tune the geometry of the experimental setup and it is presented in this contribution.
Fission decay modes of 254Fm* compound nucleus formed in 16O+238U reaction
Authors: Kaur Amandeep , Sharma Manoj K.
Published: December 2023

The quantum mechanical fragmentation theory (QMFT) based dynamical cluster-decay model (DCM) is applied to analyze the probable fission decay modes of 254Fm* compound nucleus produced in 16O+238U nuclear reaction at excitation energy EC*N =45.9 MeV. The fission valley of collective fragmentation potential and the multi-humped peaks of preformation probability P0 profile are analyzed by considering compact as well as elongated configurations of quadrupole (β2) deformed fragments. The competitive emergence of different symmetric [symmetric superlong (SL), symmetric supershort (SS)] and asymmetric [standard 1 (S1), standard 2 (S2), standard 3 (S3)] fission modes have been observed for the case of elongated configuration. The division of mass and charge in nuclear fission of 254Fm* depicts the importance of spherical and deformed magic shell closures. The most energetic light (AL and heavy (AH) decay fragments of aforementioned fission modes are identified. Moreover, the DCM-calculated fission cross-sections (σ fission) show reasonable agreement with the experimental measurements [24].
Experimental study of high-energy fission and quasi-fission with fusion- induced fission reactions at VAMOS++
Authors: Fernández D. , Caamaño M. , Ramos D. , Lemasson A. , Rejmund M. , Álvarez-Pol H. , Audouin L. , Frankland J. D. , Fernández-Domínguez B. , Galiana-Baldó E. , Piot J. , Schmitt C. , Ackermann D. , Biswas S. , Clement E. , Durand D. , Farget F. , Fregeau M. O. , Galaviz D. , Heinz A. , Henriques A. , Jacquot B. , Jurado B. , Kim Y. H. , Morfouace P. , Ralet D. , Roger T. , Teubig P. , Tsekhanovich I.
Published: December 2023

Over the past decade, inverse kinematics has been increasingly employed in experimental studies of fission. This approach has yielded a wealth of new observables that can be obtained in single measurements, enabling their analysis and correlations. One ongoing application of this technique involves a series of experiments performed at GANIL using the variable-mode, large-acceptance VAMOS++ spectrometer. A recent experiment focused on examining the survival of nuclear structure effects at high excitation energy in both fission and quasi-fission. The results of the study involved a full isotopic identification of fragments, as well as an analysis of the elemental yields their relation to fission dynamics. The results indicate that fission and quasi-fission involve different mechanisms, which could be exploited to distinguish between the two phenomena.
Proton-neutron pairing, α-like quarteting and ground/excited states of N=Z nuclei
Authors: Sandulescu Nicolae
Published: December 2023

Various studies have shown that the proton-neutron (pn) pairing correlations can be accurately described not by a condensate of Cooper pairs, as considered in the majority of mean-field calculations, but by a condensate of α-like quartets. After a short review of the quartet condensate model (QCM), it is discussed the eﬀect of the pn pairing on the ground states of N = Z nuclei, analysed recently in the framework of Skyrme-HF+QCM calculations. An interesting aspect pointed out by these calculations is the strong interdependence between all types of pairing correlations. In particular, when the isoscalar pn pairing channel is switched on, the pairing correlations are redistributed among all the pairing channels without changing significantly the total pairing energy. Due to this reason, for the majority of N = Z nuclei, the binding energy is not aﬀected much when the isoscalar pairing channel is switched on. Yet, in all calculations which include both the isovector and the isoscalar pairing forces, the isoscalar pairing correlations contribute significantly to the binding energies and coexist always with the isovector pn pairing. Finally it is presented a recent extension of the QCM approach to the excited stated of pn pairing Hamiltonians. It will be shown that the low-lying excited states of these Hamiltonians can be described by breaking a quartet from the ground state condensate and replacing it with an “excited” quartet, an approach which is analogous to the one-broken-pair approximation which is commonly used for like-particle systems.
The kink effect of the nuclear charge radii in some isotopic chains and the nucleon-nucleon tensor force within nonlinear relativistic models in the Hartree-Fock approximation
Authors: Marcos Saturnino , Niembro Ramón , López-Quelle Mercedes
Published: December 2023

Relativistic nonlinear models in the Hartree-Fock approach, with σ, ω, ρ and π mesons, are used to explore the influence of the nucleon-nucleon tensor force (tf) on the behaviour of the nuclear charge radii of the Pb isotopic chain. It is found that a part of its effect on the charge radii is channelled through its opposite effect to the spin-orbit interaction. The kink effect seems to be produced by the combination of the geometrical features of the 1i11/2 neutron orbital and its binding energy.
Recent THM investigations on neutron induced reactions at astrophysical energies
Authors: Sergi Maria Letizia , Lamia Livio , Cherubini Silvio , D’Agata Giuseppe , Di Pietro Alessia , Fernandez-Garcia Juan Pablo , Figuera Pierpaolo , Guardo Giovanni Luca , Gulino Marisa , Hayakawa Seiya , Indelicato Iolanda , La Cognata Marco , La Commara Marco , Lattuada Dario , Lattuada Marcello , Mazzocco Marco , Oliva Alessandro Alberto , Palmerini Sara , Pizzone Rosario Gianluca , Rapisarda Giuseppe Gabriele , Romano Stefano , Spartà Roberta , Spitaleri Claudio , Torresi Domenico , Tumino Aurora
Published: December 2023

Neutron induced reactions on stable and unstable nuclei play a significant role in the nucleosynthesis of the elements in the cosmos. In the last years, several efforts have been made to investigate the possibility of applying the Trojan Horse Method (THM) to neutron induced reactions mostly by using deuteron as “TH-nucleus”. Here, the main advantages of using THM will be given together with a more focused discussion on the recent 7Be(n,α)4He and the 14N(n,p)14C reactions.
Charmed Galaxies
Authors: Becker Tjus Julia , Rhode Wolfgang
Published: December 2023

The quest for finding the origins of cosmic rays has been going on for many decades. Cosmic rays as charged particles react to cosmic magnetic fields and typically travel in diffusive motion through the Universe. Their imprint on Earth therefore holds little information on their origin, and finding the sources of cosmic rays is a major challenge. The question of their origins has been a leading questions in physics and astrophysics in the past decades. To solve this riddle, a multimessenger approach is used, including cosmic-ray interaction products in the searches, specifically gamma-rays and neutrinos produced in the resulting particle showers. In this multimessenger picture, the detection of high-energy neutrinos from the cosmos by IceCube - as a unique tracer of cosmic rays - is an important piece of the puzzle. First evidence for neutrino emission from the active galaxies TXS0506+056 and NGC1068 indicates that a significant fraction comes from such sources. In this paper, the intriguing fact that gamma-rays seem to be absorbed in these sources discussed. The possibility of neutrinos being produced in regions of high photon or gas densities, together with the possibility of in the future revealing neutrinos from the decay of charmed particles, will be investigated, possibly opening a window to Charmed Galaxies.
Nuclear Astrophysics at the Low-Energy Frontiers: Updates from underground laboratories
Authors: Cavanna Francesca
Published: December 2023

Nuclear fusion reactions are the heart of nuclear astrophysics: they sensitively influence the nucleosynthesis of the elements in the earliest stages of the Universe and in all the objects formed thereafter; control the associated energy generation and neutrino luminosity; influence the evolution of stars. Unfortunately, measuring reaction cross sections at astrophysically relevant energies is exceptionally challenging due to Coulomb repulsion between nuclei, resulting in cross section values as low as fbar. Laboratorial measurements of these cross sections are often unfeasible due to overwhelming cosmic-ray-induced backgrounds. One effective solution to this problem is to conduct experiments in underground laboratories. The Laboratory for Underground Nuclear Astrophysics (LUNA) is an experimental approach based on an underground accelerator focusing on studying nuclear fusion reactions. Its primary objective is to accomplish direct measurement of cross sections for nuclear reactions that have significance in stellar and primordial nucleosynthesis. This article will present the latest findings and future objectives.
From correlations to universal behavior in few-nucleon systems
Authors: Kievsky Alejandro , Gattobigio Mario , Girlanda Luca , Viviani Michele
Published: December 2023

The deuteron, the only two-nucleon bound state, has a shallow character: its binding energy is strictly related to zero-energy parameters, the triplet scattering length 3anp and triplet effective range 3rnp. This fact places the deuteron inside the universal window, a region in which systems having a large value of the two- body scattering length are located. When the scattering length is large compared to the interaction range certain types of correlations can be observed. Increasing the number of nucleons these correlations are responsible for the particular spectrum of light nuclei as for example the lack of excited states in three- and four-nucleon systems. In this presentation some constraints imposed by the large values of the singlet and triplet scattering lengths in the spectrum of light nuclear systems are discussed.
Fractal interpolation-based micro-surface reconstruction method for composite pore walls
Authors: HU Wenlong , LUO Xidong , YANG Yu , LUO Bin , CHENG Hui
Published: December 2023

The pore wall morphology of carbon fiber reinforced composite (CFRP) laminates is one of the key factors to determine their service performance. However, due to the direction angle of the material fibers, the original micro surface morphology of the pore wall is complex and difficult to characterize. In this paper, a method to reconstruct the micro surface of the hole wall by fractal interpolation is proposed. By using a small number of data points extracted, the high-precision equivalent micro surface by fractal interpolation can be reconstructed, which can effectively characterize the composite joint surface. Firstly, the geometric features of micro surface are extracted by using the experimental measurement. Then, based on the model for fractal interpolation, an improved self affine fractal interpolation algorithm is used to reconstruct the original measured surface. Finally, the geometric and mechanical validity of fractal interpolation surface reconstruction is verified by combining geometric model and finite element model. The results show that when the sampling interval is 3~5, the geometric error and mechanical property error of the fractal interpolation method are below 10%, which can effectively characterize the original composite joint surface.
Theoretical model and experimental study on working characteristics of electromagnetic damper
Authors: FAN Shengping , LI Jing , LI Linyong , FAN Xiaopeng , LI Hualiang , GAO Nansha
Published: December 2023

An analysis model for electromagnetic damper is proposed in order to obtain the working characteristics of electromagnetic damper under different working conditions. Firstly, the inertia force and the electromagnetic force of electromagnetic damper are calculated, and the friction force is tested. Secondly, by combining the theoretical results and the test data, the working characteristic analysis model for electromagnetic damper is established. Finally, the damping characteristics and energy harvesting characteristics of the electromagnetic damper under multiple working conditions are discussed by using the present model. The working condition characteristic surface of the electromagnetic damper is obtained by using the recovered energy and equivalent damping coefficient as the coordinate plane. The results show that the error between the calculated results and the test results is below 10%. The damping force and output voltage of the electromagnetic damper are positively correlated with excitation frequency and amplitude. The excitation amplitude and frequency influence the energy harvesting characteristic and damping property deeply, respectively. The increase in load resistance reduces the energy regenerative capacity and damping capacity of the electromagnetic damper.
Updating method on geometric shape control of continuous steel box girder bridges by incremental launching construction
Authors: HAO Didi , MIAO Changqing , FANG Shisheng
Published: December 2023

A new method of deviation vector transformation of geometric shape was proposed to improve the accuracy on geometric shape control of continuous steel box girder bridges by incremental launching construction.The method correct the transfer matrix method in the ideal state where the lateral and vertical deviations of longitudinal axis at the segments can be adjusted periodically.By firstly constructing a spatial coordinate system for identifying the geometric shape of the box bridge and taking the elevation and horizontal coordinates of the control points at both ends of the installed bridge segment as the basic variables, the actual and design coordinates of the control points will be obtained in the constructed coordinate system, constructing the vector of deviation system on geometric shape and the sum of vector squares, and then the extremum problem of the partial differential equation is solved to obtain the "transformed shape" with the lowest dispersion of overall deviation.The modified term appended to transfer matrix method aforementioned for bridge segment to be installed can be obtained ultimately by deriving from the "transformed shape" and "designed shape".Engineering practice shows that the horizontal and vertical maximal deflections on the axis of the whole bridge at post construction are less than 5 and 15 mm, respectively, by using the proposed method to control the geometric shape of a continuous steel box girder bridge by incremental launching construction method, meanwhile, the horizontal and vertical deflections on the axis of the segments above the permanent piers are less than 4 and 10 mm, respectively. The theoretical method has been verified with good effect in requirement of the code.
Multi-objective topology optimization design of truss structures based on evidence theory under limited information
Authors: SU Yu , TANG Hesheng
Published: December 2023

Uncertainty information is often limited and has great discreteness, how to ensure the structure having good robustness under epistemic uncertainty becomes a technical problem for multi-objective topology optimization design. In this paper, the evidence theory is used to quantify the epistemic uncertainty; the plausibility measurement expressing upper limit of failure probability is applied to be a new evaluation of reliability. The total weight and the reliability of structures are taken as the optimization objectives, and a multi-objective robust topology optimization design model based on evidence theory is proposed. Parallelization technique based differential evolution for multi-objective optimization (DEMO) is preferable to search above robust Pareto front due to its merits of non-requirement of any gradient and superior mechanisms of non-dominate strategy. In order to verify the effectiveness of the proposed method, the multi-objective reliability optimization of a wood truss structure is implemented with considering elastic modulus and structural load as uncertain variables. According to the optimization results, six same truss specimens are made for the static random loading test. The failure probability of the truss structure is judged by the stress and node displacement obtained from the test, so as to verify the feasibility of the reliability optimization method based on evidence theory. The experimental results also indicate that the proposed method can avoid the deviation of the optimization results caused by the fluctuation of epistemic uncertainty, and provide a new method for designers to make the optimization results robust even when the data information is insufficient and the cognitive level is limited.
Vehicle distribution strategy in urban traffic by using coverage control
Authors: ZUO Lei , MENG Duo , YAN Maode , ZHANG Shouxu
Published: December 2023

In order to optimize the distribution of the urban emergency rescue vehicles and achieve the rapid response of the traffic accident, the distribution of multi-emergency rescue vehicles for the minimum rescue time is studied. According to the coverage control and the influence of traffic congestion for rescue time, the main research contents are as follows: analysis of the overall time consumption on the target area, establishment of the optimization model which considers the responsible area and the driving constraints of each vehicle for rescue time consumption. In details, for the division problem of responsible area of emergency rescue vehicle, the responsible area of each vehicle is calculated by using Voronoi region allocation principle and taking the driving time of vehicle to any point in urban road networks as evaluation index. Then, in consideration of the driving constraints in urban road networks, the constraints in the optimization model is clarified further on the premise of analyzing the vehicle kinematic characteristics. Finally, the optimal distribution position of multi-emergency rescue vehicles in the target area and the corresponding responsible area are calculated by gradient descent. The results show that the vehicle can converge to the optimal distribution position from any position in the target city, and the traffic accidents in responsible area can be timely response.
Liebe Leserinnen, liebe Leser,
Authors: Pfeifer Ute Gabriele
Published: December 2023

wann haben Sie das letzte Mal ein Gedicht oder die Strophen eines Liedes gelernt? Wenn Ihnen die Worte leicht im Gedächtnis geblieben sind, hat Ihnen der Text sicher gut gefallen. Das beruht auf dem Zusammenwirken von Lernen, angenehmen Emotionen und Behalten. Und weil Ihnen das Gedicht gefallen hat, positive Gefühle ausgelöst hat, werden Sie es so schnell nicht vergessen – es ist in Ihrem Langzeitgedächtnis gespeichert.
Relação do impacto femoroacetabular e pubalgia em jogadores profissionais de futebol de campo
Authors: Machado Jean Klay Santos , Guimarães Gabriel Henrique dos Santos , Ferreira Maurício da Camara , Nogueira Jaime Gomes
Published: December 2023

Objetivo Analisar a relação entre a pubalgia e o impacto femoroacetabular (IFA) em atletas profissionais de um clube de futebol, definindo a prevalência de pubalgia e de impacto femoroacetabular na casuística estudada.

Métodos É um estudo epidemiológico, transversal e analítico. Foram selecionados 90 atletas profissionais de futebol atuantes no período de 2019-2021. Foram acessados os prontuários para obtenção do protocolo PCMA modificado, além de exame físico ortopédico e de radiografias da bacia com incidência anteroposterior para avaliação de pubalgia e IFA, respectivamente. Critérios de Inclusão: Atletas que atuaram no clube de futebol de campo profissional na temporada de 2019 a 2021, que foram submetidos a aplicação do PCMA modificado na admissão e que assinaram o TCLE.

Resultados O IFA apresentou elevada prevalência na amostra (85.6%), o que pode ocorrer pois, no Brasil, os jovens iniciam a prática esportiva em idade muito precoce, além do fato de os jogadores nem sempre praticarem o esporte em campos adequados ou com equipamentos e supervisão adequada. Ademais, o impacto tipo CAM foi o mais frequente (62.2%). O surgimento dessas lesões é relacionado a movimentos de alta intensidade, como os vistos no futebol. Outrossim, observou-se que não há correlação de dependência entre a pubalgia e o IFA. Foi visto que o IFA estava presente em apenas 20% dos atletas queixosos de pubalgia.

Conclusão Há elevada prevalência de IFA em atletas de futebol profissional na população estudada (85.6%) e não houve relação entre o IFA e a presença de pubalgia.
Computational explorations of a deformed fuzzy sphere
Authors: Glaser L.
Published: December 2023

This work examines the deformed fuzzy sphere, as an example of a fuzzy space that can be described through a spectral triple, using computer visualizations. We first explore this geometry using an analytic expression for the eigenvalues to examine the spectral dimension and volume of the geometry. In the second part of the paper we extend the code from Glaser and Stern [J. Geom. Phys. 159, 103921 (2021)], in which the truncated sphere was visualized through localized states. This generalization allows us to examine finite spectral triples. In particular, we apply this code to the deformed fuzzy sphere as a first step in the more ambitious program of using it to examine arbitrary finite spectral triples, like those generated from random fuzzy spaces, as show in Barrett and Glaser [J. Phys. A: Math. Theor. 49, 245001 (2016)].
Differential graded vertex operator algebras and their Poisson algebras
Authors: Caradot Antoine , Jiang Cuipo , Lin Zongzhu
Published: December 2023

In this paper, we define differential graded vertex operator algebras and the algebraic structures on the associated Zhu algebras and C2-algebras. We also introduce the corresponding notions of modules, and investigate the relations between the different module categories.
Large-volume CdZnTe bar detectors characterized by laser-induced transient currents
Authors: Betušiak M. , Praus P. , Grill R. , Belas E. , Pipek J. , Bolotnikov A. E. , James R. B.
Published: December 2023

In this work, we studied the free-carrier transport properties and space-charge formation/polarization in a CdZnTe bar-shaped radiation detector using the Laser-Induced Transient Current technique. We found out that a steady-state space charge ranging from 8 × 108 to 2.1 × 109 cm−3 is formed throughout the detector at about 0.5 s following biasing. The measured current waveforms were modeled by Monte Carlo simulations after taking into account the electric and weighting fields inside the detector and shielding box. Modeling of the unpolarized waveforms revealed an exceptionally high electron mobility-lifetime product μeτe≥0.095cm2V−1. The observed formation of positive space charge in the biased detector and linear scaling of the current waveform shapes on applied bias revealed that the detector polarization is attributed to carrier injection at the anode. Measurements in pulsed and DC bias in modified electrode geometry proved the surface-charge formation.
What are the fastest routes to fusion energy?
Authors: Lerner Eric J. , Hassan Syed M. , Karamitsos-Zivkovic Ivana , Fritsch Rudolph
Published: December 2023

In recent years, the effort to develop practical fusion energy has rapidly evolved from a focus on only tokamak and laser inertial devices to include a wide array of approaches. We survey this increasingly diverse set of routes to fusion to assess what approaches are likely to lead to practical fusion with the least outlay of resources and thus are potentially the fastest routes. While a conclusive answer can only be determined once some approach actually succeeds in producing a practical fusion-energy generator, and the speed of advance depends on the allocation of resources, it is possible to arrive at tentative conclusions now. We find that basic, long-standing obstacles make the path to practical fusion more difficult, and more resource-intensive, for all approaches using deuterium fuels (DT, DHe3) as well as for approaches with low-density plasma. The approaches that combine hydrogen–boron (pB11) fuel with high-density plasma have an easier, less resource-intensive path. At present, only a few private companies have joined the government projects in actually publishing fusion yield results. However, so far these results reflect the basic advantages of high-plasma-density approaches.
Exact solution of a three-stage model of stochastic gene expression including cell-cycle dynamics
Authors: Wang Yiling , Yu Zhenhua , Grima Ramon , Cao Zhixing
Published: December 2023

The classical three-stage model of stochastic gene expression predicts the statistics of single cell mRNA and protein number fluctuations as a function of the rates of promoter switching, transcription, translation, degradation and dilution. While this model is easily simulated, its analytical solution remains an unsolved problem. Here we modify this model to explicitly include cell-cycle dynamics and then derive an exact solution for the time-dependent joint distribution of mRNA and protein numbers. We show large differences between this model and the classical model which captures cell-cycle effects implicitly via effective first-order dilution reactions. In particular we find that the Fano factor of protein numbers calculated from a population snapshot measurement are underestimated by the classical model whereas the correlation between mRNA and protein can be either over- or underestimated, depending on the timescales of mRNA degradation and promoter switching relative to the mean cell-cycle duration time.
Inner thermal layout optimization for nanofluid-filled horizontal annular pipes
Authors: Jiang Ye , Shi Zhichao , Chao Zi-chen , Wu Ming-yu , Zhou Zhifu , Hua Yue
Published: December 2023

This paper investigates the optimization of the inner thermal layout in nanofluid-filled horizontal annular pipes under natural convection conditions. Two-dimensional models of annular pipes are established using a numerical simulation approach. Then, using this as the simulation tool, the layouts of single-, triple-, and quadruple-heat-source annular pipes are optimized. The coordinates of the inner cylinders are defined as the decision variables, and the average Nusselt number (Nu) on the cold wall surface as the objective function. For the single-cylinder model, both the Bayesian optimization algorithm (BOA) and the genetic algorithm (GA) derive the same results: an axisymmetric layout where the single heat source is positioned slightly above the axis of the annulus. However, the BOA takes much less computational time than the GA and, consequently, is chosen for cases with more complex geometry. The optimization layout of the three-cylinder model also shows an axisymmetric distribution, while the result for the four-cylinder model presents a centrally symmetric distribution. Compared to the original average Nu, the optimized ones are enhanced by 17.83%, 8.36%, and 6.18% for single-, triple-, and quadruple-heat-source annular pipes, respectively. The results of this study can be used for guiding the layout design and optimization of the nanofluid-filled exchangers with multi-inner heat sources.
Studies of nonadiabatic dynamics in the singlet fission processes of pentacene dimer via tensor network method
Authors: Peng Jiawei , Hu Deping , Liu Hong , Shi Qiang , Bao Peng , Lan Zhenggang
Published: December 2023

Singlet fission (SF) is a very significant photophysical phenomenon and possesses potential applications. In this work, we try to give a rather detailed theoretical investigation of the SF process in the stacked polyacene dimer by combining the high-level quantum chemistry calculations and the quantum dynamics simulations based on the tensor network method. Starting with the construction of the linear vibronic coupling model, we explore the pure electronic dynamics and the vibronic dynamics in the SF processes. The role of vibrational modes in nonadiabatic dynamics is addressed. The results show that the super-exchange mechanism mediated by the charge-transfer state is found in both pure electronic dynamics and the nonadiabatic dynamics. Particularly the vibrational modes with the frequencies resonance with the adiabatic energy gap play very import roles in the SF dynamics. This work not only provides a deep and detailed understanding of the SF process but also verifies the efficiency of the tensor network method with the train structure that can serve as the reference dynamics method to explore the dynamics behaviors of complex systems.
Exploring mechanical properties and failure mechanisms of aramid and PBO crystals through molecular dynamics simulations
Authors: Yang Hong-Li , Zhou Ming , Li Bing , Pei Han-Wen , Sun Yu-Wei , Lu Zhong-Yuan , Sun Zhao-Yan
Published: December 2023

Molecular dynamics simulations were used to analyze the mechanical properties and failure processes of poly(p-phenylene-terephthalamide) (PPTA), poly(p-phenylene-benzimidazole-terephthalamide) (PBIA), PBIA–PPTA (formed by 1:1 copolymerization of PPTA and PBIA), and poly(p-phenylene-benzobisoxazole) (PBO) crystals at different strain rates and temperatures. The failure stress and strain were found to be linear with the temperature and logarithmic strain rate. Moreover, based on the kinetic theory of fracture and the comprehensive simulation results, we formulated a model that describes the failure stress of the aforementioned crystals under varying strain rates and temperatures. Through the analysis of the failure process, we found that in PPTA, PBIA, and PBIA–PPTA crystals, the bond failure probability is correlated with the strain rate and temperature. The examination of bond lengths and angles unveiled that bonds with larger initial aligning angles are more susceptible to failure during the strain process. Intriguingly, the stretching process induced a conformational change in the PBO molecular chain, leading to a deviation from the linear relation in its stress–strain curve.
On flow disturbances caused by pressure taps in highly elastic flows around a microfluidic cylinder
Authors: Rodrigues R. , Rodrigues T. , Campo-Deaño L.
Published: December 2023

The objective of this work is to characterize the onset of laterally asymmetric flow of viscoelastic solutions around a confined microfluidic cylinder, which was encountered in a recent study [Rodrigues et al., J. Non-Newtonian Fluid Mech. 289, 104406 (2020)]. To this end, two non-Newtonian fluids were employed in the same micro-geometry. Two microchannels were studied, both with a cylinder of diameter 75 μm, aspect ratio (channel height over width) of 0.37, and blockage ratio (cylinder diameter over channel width) of 0.28, differing only on the width of the pressure taps, located 500 μm up- and downstream from the respective cylinder face, on opposing walls. The working fluids consist of two poly(ethylene oxide) solutions: an elastic weakly shear-thinning fluid and an elastic shear-thinning fluid. Micro-Particle Image Velocimetry and streak imaging techniques were used to evaluate the flow over a Weissenberg number range 100≤Wi≤500, while maintaining a low Reynolds number, Re < 1. The elastic shear-thinning solution showed laterally asymmetric flow past the cylinder with both pressure tap designs, while with the weakly shear-thinning solution asymmetric flow was only observed with the wider pressure tap intake. In both cases, the fluids preferentially chose the cylinder/wall gap opposing the upstream pressure tap, which was found to influence the flow greatly, seemingly associated with time-dependent flow and possibly the lateral flow asymmetry itself. This work brings to light the necessary compromise between optimal pressure tap design for quality pressure measurements and minimal flow interference, due to the increased susceptibility of elastic microfluidic flows to flow perturbations.
Observing inter-well and intra-well oscillations in buckled nanomechanical systems enabled by image processing
Authors: Erdem Ege , Demiralp Berke , Pisheh Hadi S. , Firoozy Peyman , Karakurt Ahmet Hakan , Hanay M. Selim
Published: December 2023

The scanning electron microscope (SEM) recordings of dynamic nano-electromechanical systems (NEMS) are difficult to analyze due to the noise caused by low frame rate, insufficient resolution, and blurriness induced by applied electric potentials. Here, we develop an image processing platform enhanced by the physics of the underlying system to track the motion of buckling NEMS structures in the presence of high noise levels. The algorithm is composed of an image filter, two data filters, and a nonlinear regression model, which utilizes the expected form of the physical solution. The method was applied to the recordings of a NEMS beam about 150 nm wide, undergoing intra- and inter-well post-buckling states with a transition rate of approximately 0.5 Hz. The algorithm can track the dynamical motion of the NEMS and capture the dependency of deflection amplitude on the compressive force on the beam. With the help of the proposed algorithm, the transition from inter-well to intra-well motion is clearly resolved for buckling NEMS imaged under SEM.
High-efficiency broadband absorption/reflection integrated lossy acoustic metasurface via embedded microperforated wall
Authors: He Jin , Liang Qingxuan , He Hailang , Wang Miao , Li Dichen , Chen Tianning
Published: December 2023

Period phase gradient metasurface plays a great role in promoting the innovation of acoustic application devices. However, harnessing the internal thermal viscosity of the period phase gradient metasurface to realize sound absorption and non-reciprocal transmission faces the narrow working frequency band and uncontrollable efficiency. In this paper, we propose a lossy metasurface by embedded microperforated walls to realize sound redirection and absorption with high efficiency than 90% simultaneously. The phase modulation is realized using an opening channel, which can cover the 2 π phase range in a broadband frequency range by changing the channel depth. The loss introduced by the microperforated walls can achieve efficient sound energy dissipation when negative reflection occurs. The functions can be switched between wave redirection and wave absorption by rotating the metasurface. In addition, this metasurface can redirect the incident wave below −10° and absorb the incident wave above 25° over a wide frequency range from 1500 to 6500 Hz. The simulation and experiment results of our design are in excellent agreement. This research provided a new bridge to integrate wave redirection and absorption with microperforated walls and may have potential applications in acoustic sensing, sound source identification, and mechanical fault diagnosis.
Odyssey of the charge pumping technique and its applications from micrometric- to atomic-scale era
Authors: Djezzar Boualem
Published: December 2023

This paper reviews the evolution of the charge pumping (CP) technique and its applications from the micrometer-scale to the atomic-scale device era. We describe the more significant milestones of the CP technique (CPT) over the past couple of decades, giving insight into its potentialities. We start with the most popular one “traditional or conventional CP” and follow up with its different extensions in various fields like transistor reliability and radiation damage characterizations in devices fabricated with old and new semiconductor and dielectric materials. We show its easy adaptability for transistors with specific geometries. Advantages, weaknesses, as well as future tendencies of CPT and its variants, are also discussed.
A conservative sharp interface method for two-dimensional incompressible two-phase flows with phase change
Authors: Pang Bo , Ren Yi , Shen Yi , Liu Hao-Ran , Ding Hang
Published: December 2023

A conservative sharp interface method is proposed in this work to simulate two-dimensional/axisymmetric incompressible two-phase flows with phase change. In this method, we use the cut cell method to generate unstructured meshes near the interface, of which the cell edges overlap with the interface at each time step. On such mesh, the mass and heat transfer during phase change and all the jump conditions can be incorporated into the calculation of fluxes at the cell edges, to ensure that they are strictly satisfied at the interface in a sharp manner. The governing equations, including the incompressible Navier–Stokes equations, heat equation, and vapor mass fraction equation, are discretized by a second-order finite volume method in the arbitrary Lagrangian–Eulerian framework. To well couple the mass, heat, momentum, and interface evolution, the solution procedure is carefully designed and performed with several techniques. In such a way, the sharp discontinuity of the velocity, stress, temperature gradient, and vapor fraction, caused by the mass/heat transfer during phase change, can be simulated accurately and robustly. The performance of this method is systematically examined by cases of phase change at or below the saturated temperature, including vapor bubble in superheated liquid, film boiling, droplet evaporation at different relative humidity conditions, droplet evaporation under gravity, and droplet evaporation under forced convection. The applicability of the present method for incompressible two-phase flows with phase change is well demonstrated by comparing the numerical results with the benchmark, theoretical or experimental ones.