scholarly journals Long-term simulations of multi-dimensional core-collapse supernovae: Implications for neutron star kicks

2019 ◽  
Vol 71 (5) ◽  
Author(s):  
Ko Nakamura ◽  
Tomoya Takiwaki ◽  
Kei Kotake
Keyword(s):  
Neutron Star ◽  
Three Dimensional ◽  
3D Models ◽  
Quantitative Prediction ◽  
Core Collapse ◽  
Wide Range ◽  
Mass Ejection ◽  
2D And 3D ◽  
Neutrino Luminosity

Abstract Core-collapse supernovae (CCSNe) are the final stage of massive stars, marking the birth of neutron stars (NSs). The aspherical mass ejection drives a natal kick of the forming NS. In this work we study the properties of the NS kick based on our long-term hydrodynamics CCSN simulations. We perform two-dimensional (2D) simulations for ten progenitors from a 10.8 to 20$\, M_{\odot }$ star covering a wide range of the progenitor’s compactness parameter, and two three-dimensional (3D) simulations for an 11.2$\, M_{\odot }$ star. Our 2D models present a variety of explosion energies between ∼1.3 × 1050 erg and ∼1.2 × 1051 erg, and NS kick velocities between ∼100 km s−1 and ∼1500 km s−1. For the 2D exploding models, we find that the kick velocities tend to become higher with the progenitor’s compactness. This is because the high progenitor compactness results in high neutrino luminosity from the proto-neutron star (PNS), leading to more energetic explosions. Since high-compactness progenitors produce massive PNSs, we point out that the NS masses and the kick velocities can be correlated, which is moderately supported by observation. Comparing 2D and 3D models of the 11.2$\, M_{\odot }$ star, the diagnostic explosion energy in 3D is, as previously identified, higher than that in 2D, whereas the 3D model results in a smaller asymmetry in the ejecta distribution and a smaller kick velocity than in 2D. Our results confirm the importance of self-consistent CCSN modeling covering a long-term post-bounce evolution in 3D for a quantitative prediction of the NS kicks.

scholarly journals 3D hydrodynamic core-collapse SN simulations for an 11.2 M⊙ star with spectral neutrino transport

2011 ◽  
Vol 7 (S279) ◽  
pp. 409-410
Author(s):  
Tomoya Takiwaki ◽  
Kei Kotake ◽  
Yudai Suwa
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Core Collapse ◽  
Numerical Resolution ◽  
1D Model ◽  
Explosion Mechanism ◽  
Hydrodynamical Simulations ◽  
Energy Dependent ◽  
2D And 3D ◽  
Neutrino Luminosity

AbstractWe have performed three-dimensional (3D) hydrodynamical simulations of core-collapse supernovae (SNe) with multigroup neutrino transport to study non-axisymmetric effects in the context of neutrino heating explosion mechanism. By comparing one- (1D) and two dimensional (2D) results with those of 3D, we study how the increasing spatial multi-dimensionality affects the postbounce SN dynamics. The calculations were performed with an energy-dependent treatment of the neutrino transport that is solved by the isotropic diffusion source approximation scheme. In agreement with previous studies, our 1D model does not produce explosions for the 11.2 M⊙ star, while the neutrino-driven revival of the stalled bounce shock is obtained both in the 2D and 3D models. Our results show that convective matter motions below the gain radius become much more violent in 3D than 2D, making the neutrino luminosity larger for 3D. Enhanced by the large neutrino luminosity, the shock of the 3D model expands faster than that of the 2D. Our results show that the evolution of the shock is sensitive to the employed numerical resolutions. To draw a robust conclusion, 3D simulations with much higher numerical resolution and more advanced treatment of neutrino transport and gravity is needed.

scholarly journals A systematic study of proto-neutron star convection in three-dimensional core-collapse supernova simulations

2020 ◽  
Vol 492 (4) ◽  
pp. 5764-5779 ◽  
Author(s):  
Hiroki Nagakura ◽  
Adam Burrows ◽  
David Radice ◽  
David Vartanyan
Keyword(s):  
Neutron Star ◽  
Systematic Study ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Core Collapse ◽  
Core Collapse Supernova ◽  
Tau Neutrinos ◽  
The Impact ◽  
Proto Neutron Star

ABSTRACT This paper presents the first systematic study of proto-neutron star (PNS) convection in three dimensions (3D) based on our latest numerical fornax models of core-collapse supernova (CCSN). We confirm that PNS convection commonly occurs, and then quantify the basic physical characteristics of the convection. By virtue of the large number of long-term models, the diversity of PNS convective behaviour emerges. We find that the vigour of PNS convection is not correlated with CCSN dynamics at large radii, but rather with the mass of PNS − heavier masses are associated with stronger PNS convection. We find that PNS convection boosts the luminosities of νμ, ντ, $\bar{\nu }_{\mu }$, and $\bar{\nu }_{\tau }$ neutrinos, while the impact on other species is complex due to a competition of factors. Finally, we assess the consequent impact on CCSN dynamics and the potential for PNS convection to generate pulsar magnetic fields.

scholarly journals Extending In-Plane Impedance Measurements from 2D to 3D Cultures: Design Considerations

2021 ◽  
Vol 8 (1) ◽  
pp. 11
Author(s):  
Sorel E. De Leon ◽  
Lana Cleuren ◽  
Zay Yar Oo ◽  
Paul R. Stoddart ◽  
Sally L. McArthur
Keyword(s):  
Three Dimensional ◽  
3D Culture ◽  
Collagen Gel ◽  
Impedance Measurement ◽  
Impedance Spectrum ◽  
3D Models ◽  
Low Frequencies ◽  
3D Cell Cultures ◽  
3D Collagen ◽  
2D And 3D

Three-dimensional (3D) cell cultures have recently emerged as tools for biologically modelling the human body. As 3D models make their way into laboratories there is a need to develop characterisation techniques that are sensitive enough to monitor the cells in real time and without the need for chemical labels. Impedance spectroscopy has been shown to address both of these challenges, but there has been little research into the full impedance spectrum and how the different components of the system affect the impedance signal. Here we investigate the impedance of human fibroblast cells in 2D and 3D collagen gel cultures across a broad range of frequencies (10 Hz to 5 MHz) using a commercial well with in-plane electrodes. At low frequencies in both 2D and 3D models it was observed that protein adsorption influences the magnitude of the impedance for the cell-free samples. This effect was eliminated once cells were introduced to the systems. Cell proliferation could be monitored in 2D at intermediate frequencies (30 kHz). However, the in-plane electrodes were unable to detect any changes in the impedance at any frequency when the cells were cultured in the 3D collagen gel. The results suggest that in designing impedance measurement devices, both the nature and distribution of the cells within the 3D culture as well as the architecture of the electrodes are key variables.

scholarly journals Swift/XRT, Chandra, and XMM–Newton observations of IGR J17091–3624 as it returns into quiescence

2020 ◽  
Vol 497 (1) ◽  
pp. 1115-1126
Author(s):  
M Pereyra ◽  
D Altamirano ◽  
J M C Court ◽  
N Degenaar ◽  
R Wijnands ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Time Scales ◽  
Strong Evidence ◽  
Spectral Properties ◽  
X Ray ◽  
Term Evolution ◽  
Wide Range ◽  
Low Mass

ABSTRACT IGR J17091–3624 is a low-mass X-ray binary (LMXB), which received wide attention from the community thanks to its similarities with the bright black hole system GRS 1915+105. Both systems exhibit a wide range of highly structured X-ray variability during outburst, with time-scales from few seconds to tens of minutes, which make them unique in the study of mass accretion in LMXBs. In this work, we present a general overview into the long-term evolution of IGR J17091–3624, using Swift/XRT observations from the onset of the 2011–2013 outburst in 2011 February till the end of the last bright outburst in 2016 November. We found four re-flares during the decay of the 2011 outburst, but no similar re-flares appear to be present in the latter one. We studied, in detail, the period with the lowest flux observed in the last 10 yr, just at the tail end of the 2011–2013 outburst, using Chandra and XMM-Newton observations. We observed changes in flux as high as a factor of 10 during this period of relative quiescence, without strong evidence of softening in the spectra. This result suggests that the source has not been observed at its true quiescence so far. By comparing the spectral properties at low luminosities of IGR J17091–3624 and those observed for a well-studied population of LMXBs, we concluded that IGR J17091–3624 is most likely to host a black hole as a compact companion rather than a neutron star.

Effects of Weld Geometry Size on the Pressure-Bearing Capacity of an API X80 LSAW Pipe

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Gui-ying Qiao ◽  
Yu-meng Liu ◽  
Jun-si Wang ◽  
Fu-ren Xiao
Keyword(s):  
Stress Distribution ◽  
Weld Joint ◽  
Large Diameter ◽  
Three Dimensional ◽  
3D Models ◽  
Welding Parameter ◽  
Weld Geometry ◽  
Transmission Pipeline ◽  
2D And 3D ◽  
Submerged Arc

Abstract The weld joint is the weakest zone of a longitudinal-seam submerged arc welded (LSAW) pipe, which has great effects on its in-service properties and safety. The weld geometry and shape of the weld joint are important factors that affect the mechanical properties of the pipe. In this work, two-dimensional (2D) and three-dimensional (3D) finite element models (FEMs) of a large-diameter, heavy-wall API X80 LSAW pipe were established, and the stress distribution of the pipe was calculated to simulate the in-service gas transmission pipeline. Results showed that the stress distribution calculated by both 2D and 3D models are similar. Consequently, the effects of weld geometry, softening of heat affected zone (HAZ), and strength matching of the weld joint on bearing pressure capability of the pipe were analyzed, and the results showed that the bearing pressure capability of the pipe can be improved by controlling these parameters. These results are beneficial in providing references for welding parameter design and improved properties of the X80 LSAW pipe.

Linear and Nonlinear Model of Cutting Forces in Peripheral Milling: A Comparison Between 2D and 3D Models

2010 ◽  
Author(s):  
Hamed Moradi ◽  
Mohammad R. Movahhedy ◽  
Gholamreza Vossoughi
Keyword(s):  
Cutting Forces ◽  
Nonlinear Models ◽  
Three Dimensional ◽  
Chip Thickness ◽  
Maximum Error ◽  
3D Models ◽  
Peripheral Milling ◽  
Third Order ◽  
Order Polynomial ◽  
2D And 3D

Peripheral milling is extensively used in manufacturing processes, especially in aerospace industry where end mills are used for milling of wing parts and engine components. Knowledge of the cutting forces is the first necessary stage in analysis of the milling process. In this paper, cutting forces are presented for both two and three dimensional models. Instead of the common linear dependency of cutting forces to the cut chip thickness, two nonlinear models are presented. In the first model, cutting forces are considered as a function of chip thickness with a complete third order polynomial. In the second one, the quadratic and constant terms of the third order polynomial are set to zero. Results show about 2–3% and 2–7% maximum error between the linear, first and second nonlinear models, for 2D and 3D models, respectively. According to the simulation results, both the 2D and 3D models with second type of nonlinearity can be effectively used in practice. The advantage of such modelling is its simplicity in nonlinear analysis of the problem based on perturbation techniques.

scholarly journals Embedding X.509 Digital Certificates in Three-Dimensional Models for Authentication, Authorization, and Traceability of Product Data

2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Thomas D. Hedberg ◽  
Sylvere Krima ◽  
Jaime A. Camelio
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Product Lifecycle Management ◽  
Product Lifecycle ◽  
International Telecommunication Union ◽  
Product Data ◽  
International Telecommunication ◽  
Wide Range ◽  
Digital Certificates ◽  
Three Dimensional Models

Exchange and reuse of three-dimensional (3D) product models are hampered by the absence of trust in product-lifecycle data quality. The root cause of the missing trust is years of “silo” functions (e.g., engineering, manufacturing, and quality assurance) using independent and disconnected processes. Those disconnected processes result in data exchanges that do not contain all of the required information for each downstream lifecycle process, which inhibits the reuse of product data and results in duplicate data. The X.509 standard, maintained by the Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T), was first issued in 1988. Although originally intended as the authentication framework for the X.500 series for electronic directory services, the X.509 framework is used in a wide range of implementations outside the originally intended paradigm. These implementations range from encrypting websites to software-code signing, yet X.509 certificate use has not widely penetrated engineering and product realms. Our approach is not trying to provide security mechanisms, but equally as important, our method aims to provide insight into what is happening with product data to support trusting the data. This paper provides a review of the use of X.509 certificates and proposes a solution for embedding X.509 digital certificates in 3D models for authentication, authorization, and traceability of product data. This paper also describes an application within the aerospace domain. Finally, the paper draws conclusions and provides recommendations for further research into using X.509 certificates in product lifecycle management (PLM) workflows to enable a product lifecycle of trust.

scholarly journals Three-dimensional Boltzmann-Hydro Code for Core-collapse in Massive Stars. II. The Implementation of Moving-mesh for Neutron Star Kicks

2017 ◽  
Vol 229 (2) ◽  
pp. 42 ◽  
Author(s):  
Hiroki Nagakura ◽  
Wakana Iwakami ◽  
Shun Furusawa ◽  
Kohsuke Sumiyoshi ◽  
Shoichi Yamada ◽  
...  
Keyword(s):  
Neutron Star ◽  
Massive Stars ◽  
Three Dimensional ◽  
Moving Mesh ◽  
Core Collapse

scholarly journals Three Dimensional Weightbearing CT Assessment of Metatarsal Osteotomies for Hallux Valgus Correction

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0015
Author(s):  
Jarrett D. Cain ◽  
Jordan T. Stolle ◽  
Sorin Siegler
Keyword(s):  
Hallux Valgus ◽  
Weight Bearing ◽  
Three Dimensional ◽  
3D Models ◽  
Two Dimensions ◽  
Axial Plane ◽  
Ct Scans ◽  
First Metatarsal ◽  
3D Measurements ◽  
2D And 3D

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Hallux valgus (HV) is a tri-plane deformity of the foot corresponding to a medial deviation of the first metatarsal and a lateral deviation of the hallux. Understanding key angles between bones, as well as how these deformity changes in each plane, is critical to generating pre-operative insights into the most effective surgical correction of the deformity. While two- dimenional (2D) imaging can provide some information; utilizing three-dimensional (3D) imaging can include more precise and accurate measures of hallux valgus. The purpose of this study is to evaluate the metatarsal osteotomies for correction of hallux valgus deformity in axial, coronal and sagittal plane with 2D and 3D measurements with the hypothesis that 3D measurements will provide greater accuracy of pre and post surgical changes Methods: Ten cadaveric specimens were selected and weight-bearing CT scans were taken pre operatively with an applied an axial load of 80 pounds. Midshaft osteotomies were then performed on the cadaveric specimens followed by weight-bearing CT scans taken post-operatively.3D models of the pre-operative and post-operative specimens were created and differences in pre and post operative changes were analyzed using conventional 2D and 3D models of the first metatarsal (M1), second metatarsal (M2), fifth metatarsal (M5), and proximal phalanx of the hallux (PP1) using a paired student t-test. Quantitative examination of foot and ankle offset (FAO) alignment along with congruity of first metatarsal phalangeal and first tarsometatarsal joints Results: 3D measurements of the Inter-Metatarsal (IM) Angle, was 12.3 degrees pre-opeative and 10.4 degrees post-operative with no significant differences in all three planes while the M1M5 Angle, measured between the principle axes of the first metatarsal and fifth metatarsal was 25.3 degrees pre-operative and 22.0 degrees post-operative were statistically significant with the greatest change in the axial plane. 2D measurements of the hallux valgus angle, measured the longitudineal axes of the first metatarsal and proximal phalange of the hallux was 22.6 degrees pre opereative and 21.7 degrees post opereative with no statistical difference while the metatarsal parabola, measured in two dimensions projected onto the axial plane was 157.1 degrees before and 141.5 degrees after surgery was statistical significant. Conclusion: When comparing 2D and 3D pre and post surgical hallux valgus values, the only significant differences were identified in the absolute M1M5 values in the axial plane and a significant change was also observed in the metatarsal parabola angle. While the metatarsal parabola angle are sensitive measures, these results suggest that the M1 M5 angle allows for precise, efficient measurements in axial, coronal and sagittal planes that is previously unknown through two-dimensional radiographic measurements for quantifying the effect of metatarsal osteotomies on hallux valgus

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