Frontiers in Physics最新文献

{"title":"Detection of natural pulse waves (PWs) in 3D using high frame rate imaging for anisotropy characterization","authors":"Jack Sauvage, Safa Moustefaoui, Stefano Fiorentini, Maelys Venet, Solveig Fadnes, Lasse Lovastakken, Olivier Villemain, Sébastien Salles","doi":"10.3389/fphy.2024.1450631","DOIUrl":"https://doi.org/10.3389/fphy.2024.1450631","url":null,"abstract":"IntroductionNumerous studies have shown that natural mechanical waves have the potential to assess the elastic properties of the myocardium. When the Aortic and Mitral valves close, a shear wave is produced, which provides insights into tissue stiffness. In addition, the Atrial Kick (AK) generates a wave similar to Pulse Waves (PWs) in arteries, providing another way to assess tissue stiffness. However, tissue anisotropy can also impact PW propagation, which is currently underexplored. This study aims to address this gap by investigating the impact of anisotropy on PW propagation in a phantom.MethodsTube phantoms were created using Polyvinyl Alcohol (PVA). Anisotropy was induced between two sets of two freeze-thaw cycles by stretching and twisting the material. The study first tests and validates the procedure of making helical anisotropic vessel phantoms using the shear wave imaging technique (by estimating the shear wave speed at different probe angles). Using plane wave ultrasound tomography synchronized with a peristaltic pump, 3D high frame rate imaging is performed and used to detect the 3D propagation pattern of PW for each manufactured vessel phantom. Finally, the study attempts to extract the anisotropic coefficient of the vessel using pulse wave propagation angle.ResultsThe Shear wave imaging results obtained for the isotropic vessel show very similar values for each probe angle. On the contrary, the results obtained for the axial anisotropy vessel show a region with a higher shear wave speed at about 0°, corresponding to the long axis of the vessel. Finally, the results obtained for the helical anisotropy depicted increasing shear wave velocity value from −20° to 20°. For the axial phantom, the wavefront of the pulse wave is perpendicular to the long axis of the vessel, while oriented for the helical anisotropic vessels phantom. The pulse wave propagation angle increased with the number of twists made during the vessel manufacturing.DiscussionThe results show that anisotropy can be induced in PVA vessel phantoms by stretching and twisting the material in freeze-thaw cycles. The findings also suggest that vessel anisotropy affects pulse wave propagation angles. Estimating the pulse wave propagation angle may be interesting in characterizing tissue anisotropy in organs where such waves are naturally present.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"3 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable continuous wave Yb:CaWO4 laser operating in NIR spectral region","authors":"Hao Yu, Chong Chen, Yong-Liang Li","doi":"10.3389/fphy.2024.1468722","DOIUrl":"https://doi.org/10.3389/fphy.2024.1468722","url":null,"abstract":"A tunable continuous wave (CW) Yb:CaWO<jats:sub>4</jats:sub> laser operating in near infrared (NIR) spectral region is demonstrated by pumping with a diode laser. Continuously broadband tunable wavelengths are obtained in two polarizations by rotating the Lyot filter. The tuning widths of the output wavelengths in the π- and σ-polarizations are 42 nm (from 1005.2 nm to 1047.2 nm) and 41.8 nm (from 1005.1 nm to 1046.9 nm), respectively. At an absorbed pump power of 15.6 W at 976 nm, the maximum output powers in the π- and σ-polarizations are 5.2 W at 1026.2 nm and 4.7 W at 1028.1 nm, respectively. To the best of our knowledge, this is the first tunable laser operation by using Yb:CaWO<jats:sub>4</jats:sub> crystal.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"12 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of the influence of different shapes of shaft sections on dust transportation","authors":"Jie Liu, Xuehua Luo, Wanqing Wang, Liangyun Teng, Chenwei Hao, Fei Cai, Yi Chen","doi":"10.3389/fphy.2024.1437171","DOIUrl":"https://doi.org/10.3389/fphy.2024.1437171","url":null,"abstract":"Large amounts of dust are generated during digging operations in underground mines, and the transportation of dust is affected by the shape of the roadway section. In order to know the dust transportation law of different cross-section shapes when digging. Fluent software was used to simulate the distribution of wind flow field, dust transportation trajectory, and dust quality concentration in roadways with semicircular arch, three-centered arch, rectangle and trapezium, and then analyze and compare the influence of four cross-section shapes on dust transportation, and use gray correlation analysis to investigate the correlation between the time needed to reduce the dust quality concentration of the roadway to the safe value and the ventilation air volume and air supply distance. The results of the study show that the wind speed in the roadway is in the following order from high to low: rectangle &amp;gt; trapezium &amp;gt; three-centered arch &amp;gt; semicircular arch. Dust particles of each size rubbed each other after blasting, and there were fewer dust particles with larger sizes in the three-centered arch roadway. Both the air supply distance and ventilation air volume impact the dust removal effect; when the air supply distances are 5 m and 10 m, the three-centered arch has a better dust removal effect; when the air supply distances are 15 m and 20 m, the effect is better in the rectangular roadway and trapezoidal roadway; and when the ventilation air volume is increased, it is the three-centered arch. Through the gray correlation analysis, it can be seen that in order to improve the construction environment in the roadway after blasting, the rectangular section can be chosen when considering the air supply distance, and the three-centered arch can be chosen when considering the ventilation air volume.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"14 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bonner sphere measurements of high-energy neutron spectra from a 1 GeV/u 56Fe ion beam on an aluminum target and comparison to spectra obtained by Monte Carlo simulations","authors":"Augusto Di Chicco, Felix Horst, Daria Boscolo, Christoph Schuy, Uli Weber, Miroslav Zboril","doi":"10.3389/fphy.2024.1456472","DOIUrl":"https://doi.org/10.3389/fphy.2024.1456472","url":null,"abstract":"The goal of this work is to characterize the secondary neutron spectra produced by 1 GeV/u<jats:sup>56</jats:sup>Fe beam colliding with a thick cylindric aluminum target and to perform a quantitative comparison with simulated results obtained with Monte Carlo codes. The measurements were performed using extended-range Bonner sphere spectrometers at two positions (15° and 40°) with respect to the beam direction. The secondary radiation field was simulated using four Monte Carlo codes (FLUKA, MCNP6, Geant4 and PHITS) and several physical models of nuclei transport and interaction. Neutron and proton energy distributions were simulated for the experimental measurement positions. The simulated neutron spectra, together with data measured with Bonner sphere spectrometers, after carrying out the correction of the contributions induced by the secondary protons, were used as input for the MAXED spectrum unfolding code to obtain the measured neutron spectra. Unfolded neutron spectra were compared with simulated ones to carry out a quantitative analysis of the performance of the chosen Monte Carlo codes and their corresponding physical models. This comparison showed that, because of experimental uncertainties and physical models, there are no unique solutions for each measurement location, but a range of solutions where the true experimental neutron spectra probably lie. The results showed deviations between 4.23% and 8.42% for some simulated spectra. Regarding the total integral values of neutron fluence and ambient equivalent dose, the unfolded neutron spectra showed deviations lower than 2%.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"24 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-destructive testing based on Unet-CBAM network for pulsed thermography","authors":"Chenghao Wu, Dan Wu, Pengfei Zhu","doi":"10.3389/fphy.2024.1458194","DOIUrl":"https://doi.org/10.3389/fphy.2024.1458194","url":null,"abstract":"Infrared thermography (IRT) is a non-destructive testing technique that can detect the internal defects of materials. In the detection of austenitic stainless-steel pipes with large curvature, image noise caused by uneven heating is difficult to avoid. Traditional image processing methods are less effective. According to previous works, a supervised neural network was proposed in this paper using Unet network and convolutional block attention module. Existing image processing method and networks were used to compare with the proposed method. The results show that the proposed method can remove the noise caused by uneven heating, and detect all subsurface defects in stainless-steel pipe.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"12 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intelligent diagnostic method for developmental hip dislocation","authors":"Hang Sun, Hong Li, Yuhang Zhao, Shinong Pan","doi":"10.3389/fphy.2024.1358652","DOIUrl":"https://doi.org/10.3389/fphy.2024.1358652","url":null,"abstract":"BackgroundDevelopmental dislocation of the hip joint (DDH) is a condition that severely threatens children’s healthy growth. Without timely and correct treatment, it will lead to osteoarthritis and hip dysfunction in the evolution of children.ObjectiveIt is essential to develop an intelligent model for diagnosing hip dislocation and performing accurate quantitative analysis.MethodsIn this paper, 46 cases of computed tomography (CT) images were retrospectively collected, including 19 cases of hip dislocation and 27 cases of healthy people. The experiment first uses ITK-SNAP to sketch the ilium and femoral head in the original image. Then, it uses 3D U-Net to send the label of the background, ilium, and femoral head into three channels, respectively, to realize the three-dimensional segmentation of the ilium and femoral head. Next, the extraction of the surface of the acetabulum and femoral head is performed. Subsequently, the erroneous points are eliminated, and the spherical surfaces of the acetabulum and femoral head are fitted using the least squares method. Ultimately, the spherical center distance is calculated quantitatively to predict whether the hip joint is dislocated.ResultsUnder the independent test set, the segmentation average dice coefficients of the ilium and femoral head are 89% and 93%, respectively. The spherical center distance between the acetabulum and femoral head is calculated quantitatively. If the value exceeds 10 mm, it is considered a hip dislocation. Compared with the doctor’s diagnosis, the accuracy result is 94.4%.ConclusionThis paper successfully implements a precise and automated intelligent diagnostic system for the identification of hip dislocation. Commencing with the development of a 3D segmentation algorithm for the ilium and femoral head, we further introduce a novel method that computes the spherical distance for the prediction of hip dislocation. This approach provides robust quantitative analysis, thereby facilitating more informed clinical decision-making.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"74 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shallow crustal structure detection of the upper crust at Anqiu-Juxian Fault in the Tanlu fault zone","authors":"Qilong Huang, Xiaoping Fan, Wei Fu, Peng Zhang, Tuo Zheng, Yunze Liu, Tiantian Zhang, Shiyu Ren, Qinghui Wang, Zhiwen Liu, Ting Qian","doi":"10.3389/fphy.2024.1458844","DOIUrl":"https://doi.org/10.3389/fphy.2024.1458844","url":null,"abstract":"Within the Tan-Lu Fault Zone, the largest active tectonic belt in eastern China, the Anqiu-Juxian Fault exhibits the most recent activity period, evident surface traces, and highest seismic hazard, making it a Holocene active fault. This study utilized the vertical component continuous data observed by 100 short-period temporary stations from August 1–21, 2023, and extracted 1,944 Rayleigh wave group velocity dispersion curves within the period of 0.2–4 s. Using the direct surface wave tomography method, we calculated a high-resolution 3-D shear-wave velocity structure at depths of 0.2–1.25 km within the study area. Our results are summarized as follows: 1) The development of faults F<jats:sub>1</jats:sub>, F<jats:sub>2</jats:sub>, and F<jats:sub>5</jats:sub> in the Tan-Lu Fault Zone highly correlated with the shear-wave velocity anomalies at depths &amp;gt;0.8 km. Specifically, fault F<jats:sub>5</jats:sub> comprised two boundary faults, F<jats:sub>5-1</jats:sub> and F<jats:sub>5-2</jats:sub>, which together controlled a Cenozoic depression covered by a thick, low-velocity sediment layer. 2) The complex velocity structure characteristics in the Suqian area revealed that the influence of faults on the sedimentary layers in the Suqian area was not expressed as an overall uplift or subsidence of the block but rather as differential subsidence. 3) Near Sankeshu, the F<jats:sub>5</jats:sub> fault formed a small pull-apart basin. The latest activity in this pull-apart basin has shifted to the fault in the center of the basin, indicating that the pull-apart basin has entered the extinction stage.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"25 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Free energy calculations in biomolecule-nanomaterial interactions","authors":"Hongze Fu, Yinbang Zhu, Qu Chen","doi":"10.3389/fphy.2024.1469515","DOIUrl":"https://doi.org/10.3389/fphy.2024.1469515","url":null,"abstract":"In computational chemistry and molecular modeling, the interactions between biomolecules (BMs) and nanomaterials (NMs) play a crucial role in various physical and biological processes, and have significant implications in material discovery and development. While there is extensive literature on free energy calculations for drug-target interactions, reviews specifically addressing BM-NM interactions are relatively scarce. This manuscript aims to fill in this gap by presenting a comprehensive overview of the most widely used and well-established methods for free energy calculations. It provides a detailed analysis of the advantages and limitations of these methods and discusses their applicability to BM-NM systems. This work is intended to offer insights into free energy calculations and serve as a guide for future research in this field.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"211 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A kinetic study of fusion burn waves in compressed deuterium–tritium and proton–boron plasmas","authors":"Michael J. Lavell, Ayden J. Kish, Andrew T. Sexton, Eugene S. Evans, Ibrahim Mohammad, Sara Gomez-Ramirez, William Scullin, Marcus Borscz, Sergey Pikuz, Thomas A. Mehlhorn, Max Tabak, Greg Ainsworth, Adam B. Sefkow","doi":"10.3389/fphy.2024.1440037","DOIUrl":"https://doi.org/10.3389/fphy.2024.1440037","url":null,"abstract":"We present particle-in-cell simulations with Monte Carlo collisions of fusion burn waves in compressed deuterium–tritium and proton–boron plasmas. We study the energy balance in the one-dimensional expansion of a hot-spot by simulating Coulomb collisions, fusion reactions, and bremsstrahlung emission with a Monte Carlo model and inverse bremsstrahlung absorption using a new PIC model. This allows us to self-consistently capture the alpha particle heating and radiative losses in the expanding hot-spot and surrounding cold fuel. After verifying our model in a code-to-code comparison with both kinetic and fluid codes for the case of a deuterium–tritium hot-spot, we simulate the expansion of a proton–boron hot-spot initialized at 200 keV and 1,000 g/<jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:msup><mml:mrow><mml:mtext>cm</mml:mtext></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math></jats:inline-formula>. Our model predicts that energy radiated by the hot-spot is recaptured by the surrounding high-density opaque fuel reducing the expansion work done by the propagating burn wave. As a result, we find the net fusion energy produced over the course of $20$∼ps is twice the initial hot-spot energy independent of whether radiation physics is included.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"10 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"State estimation for Markovian jump Hopfield neural networks with mixed time delays","authors":"Lili Guo, Wanhui Huang","doi":"10.3389/fphy.2024.1447788","DOIUrl":"https://doi.org/10.3389/fphy.2024.1447788","url":null,"abstract":"Markovian jump Hopfield NNs (MJHNNs) have received considerable attention due to their potential for application in various areas. This paper deals with the issue of state estimation concerning a category of MJHNNs with discrete and distributed delays. Both time-invariant and time-variant discrete delay cases are taken into account. The objective is to design full-order state estimators such that the filtering error systems exhibit exponential stability in the mean-square sense. Two sufficient conditions on the mean-square exponential stability of MJHNNs are established utilizing augmented Lyapunov–Krasovskii functionals, the Wirtinger–based integral inequality, the Bessel-Legendre inequality, and the convex combination inequality. Then, linear matrix inequalities-based design methods for the required estimators are developed through eliminating nonlinear coupling terms. The feasibility of these linear matrix inequalities can be readily verified via available Matlab software, thus enabling numerically tractable implementation of the proposed design methods. Finally, two numerical examples with simulations are provided to demonstrate the applicability and less conservatism of the proposed stability criteria and estimators. Lastly, two numerical examples are given to demonstrate the applicability and reduced conservatism of the proposed stability criteria and estimator design methods. Future research could explore further refinement of these analysis and design results, and exporing their extention to more complex neural network models.","PeriodicalId":12507,"journal":{"name":"Frontiers in Physics","volume":"2 1","pages":""},"PeriodicalIF":3.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}