Online in situ prediction of 3-D flame evolution from its history 2-D projections via deep learning

2019 ◽  
Vol 875 ◽  
Author(s):  
Jianqing Huang ◽  
Hecong Liu ◽  
Weiwei Cai
Keyword(s):  
Deep Learning ◽  
Large Scale ◽  
Proof Of Concept ◽  
Time Resolved ◽  
Computational Costs ◽  
Rapid Prediction ◽  
Computational Fluid Dynamics Cfd ◽  
In Situ Prediction ◽  
First Time

Online in situ prediction of 3-D flame evolution has been long desired and is considered to be the Holy Grail for the combustion community. Recent advances in computational power have facilitated the development of computational fluid dynamics (CFD), which can be used to predict flame behaviours. However, the most advanced CFD techniques are still incapable of realizing online in situ prediction of practical flames due to the enormous computational costs involved. In this work, we aim to combine the state-of-the-art experimental technique (that is, time-resolved volumetric tomography) with deep learning algorithms for rapid prediction of 3-D flame evolution. Proof-of-concept experiments conducted suggest that the evolution of both a laminar diffusion flame and a typical non-premixed turbulent swirl-stabilized flame can be predicted faithfully in a time scale on the order of milliseconds, which can be further reduced by simply using a few more GPUs. We believe this is the first time that online in situ prediction of 3-D flame evolution has become feasible, and we expect this method to be extremely useful, as for most application scenarios the online in situ prediction of even the large-scale flame features are already useful for an effective flame control.

scholarly journals Spatial scales of temperature and salinity variability estimated from Argo observations

2015 ◽  
Vol 12 (4) ◽  
pp. 1793-1814
Author(s):  
F. Ninove ◽  
P. Y. Le Traon ◽  
E. Remy ◽  
S. Guinehut
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Deep Ocean ◽  
General Tendency ◽  
Zero Crossing ◽  
Tropical Regions ◽  
Covariance Functions ◽  
Salinity Variability ◽  
First Time

Abstract. Argo observations from 2005 to 2013 are used to characterize spatial scales temperature and salinity variations from the surface down to 1500 m. Simulations are first performed to analyze the sensitivity of results to Argo sampling; they show that several years of Argo observations are required to estimate the spatial scales of ocean variability over 20° × 20° boxes. Spatial scales are then computed over several large scale areas. Zonal and meridional spatial scales (Lx and Ly which are also zero crossing of covariance functions) vary as expected with latitudes. Scales are of about 100 km at high latitudes and more of 700 km in the Indian and Pacific equatorial/tropical regions. Zonal and meridional scales are similar: except in these tropical/equatorial regions where zonal scales are much larger (by a factor of 2 to 3) than meridional scales. Spatial scales are the largest close to the surface and have a general tendency for temperature to increase in deeper layers. There are significant differences between temperature and salinity scales, in particular, in the deep ocean. Results are consistent with previous studies based on sparse in-situ observations or satellite altimetry. They provide, however, for the first time a global description of temperature and salinity scales of variability and a characterization of their variations according to depths.

Time resolved growth of membrane stabilized silver NPs and their catalytic activity

RSC Advances ◽  
2014 ◽  
Vol 4 (103) ◽  
pp. 59379-59386 ◽  
Author(s):  
Sabyasachi Patra ◽  
Debasis Sen ◽  
Ashok K. Pandey ◽  
J. Bahadur ◽  
S. Mazumder ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Catalytic Activity ◽  
Growth Kinetics ◽  
Nanocomposite Membranes ◽  
Time Resolved ◽  
Catalytic Application ◽  
Silver Nps ◽  
First Time ◽  
Kinetics Of

Growth kinetics of membrane stabilized silver nanoparticles have been studied for the first time with time resolved in situ SAXS. The catalytic application of nanocomposite membranes thus formed has also been explored.

In Situ Time-Resolved X-Ray Diffraction Investigation of the ω→ψ Transition in Al-Cu-Fe Quasicrystal-Forming Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 943-947 ◽  
Author(s):  
E. Otterstein ◽  
R. Nicula ◽  
J. Bednarčík ◽  
M. Stir ◽  
E. Burkel
Keyword(s):  
Large Scale ◽  
Applied Pressure ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
In Situ Xrd ◽  
Kinetics Of

Quasicrystals are aperiodic long-range ordered solids with a high potential for many modern applications. Interest is nowadays paid to the development of economically viable large-scale synthesis procedures of quasicrystalline materials involving solid-state transformations. The kinetics of the high-temperature phase transition from the complex ω-phase to the icosahedral quasicrystalline (iQC) ψ-phase in AlCuFe nanopowders was here examined by in-situ time-resolved X-ray diffraction experiments using synchrotron radiation. In-situ XRD experiments will allow insight on the influence of uniaxial applied pressure on the kinetics of phase transitions leading to the formation of single-phase QC nanopowders and further contribute to the optimization of sintering procedures for nano-quasicrystalline AlCuFe alloy powders.

scholarly journals Deep learning for Sunyaev–Zel’dovich detection in Planck

2020 ◽  
Vol 634 ◽  
pp. A81
Author(s):  
V. Bonjean
Keyword(s):  
Deep Learning ◽  
Galaxy Clusters ◽  
Large Scale ◽  
Galaxy Cluster ◽  
Proof Of Concept ◽  
Microwave Background ◽  
Large Scale Structures ◽  
Hot Gas ◽  
Scale Structures ◽  
The Universe

The Planck collaboration has extensively used the six Planck HFI frequency maps to detect the Sunyaev–Zel’dovich (SZ) effect with dedicated methods, for example by applying (i) component separation to construct a full-sky map of the y parameter or (ii) matched multi-filters to detect galaxy clusters via their hot gas. Although powerful, these methods may still introduce biases in the detection of the sources or in the reconstruction of the SZ signal due to prior knowledge (e.g. the use of the generalised Navarro, Frenk, and White profile model as a proxy for the shape of galaxy clusters, which is accurate on average but not for individual clusters). In this study, we use deep learning algorithms, more specifically, a U-net architecture network, to detect the SZ signal from the Planck HFI frequency maps. The U-net shows very good performance, recovering the Planck clusters in a test area. In the full sky, Planck clusters are also recovered, together with more than 18 000 other potential SZ sources for which we have statistical indications of galaxy cluster signatures, by stacking at their positions several full-sky maps at different wavelengths (i.e. the cosmic microwave background lensing map from Planck, maps of galaxy over-densities, and the ROSAT X-ray map). The diffuse SZ emission is also recovered around known large-scale structures such as Shapley, A399–A401, Coma, and Leo. Results shown in this proof-of-concept study are promising for potential future detection of galaxy clusters with low SZ pressure with this kind of approach, and more generally, for potential identification and characterisation of large-scale structures of the Universe via their hot gas.

Formation of hydroxysulphate and hydroxycarbonate green rusts in the presence of zinc using time-resolved in situ small and wide angle X-ray scattering

2008 ◽  
Vol 72 (1) ◽  
pp. 159-162 ◽  
Author(s):  
I. A. M. Ahmed ◽  
S. Shaw ◽  
L. G. Benning
Keyword(s):  
Unit Cell ◽  
Wide Angle ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ph Dependent ◽  
Green Rusts ◽  
First Time ◽  
Ray Scattering

AbstractThe formation and transformation of hydroxysulphate (GRSO4) and hydroxycarbonate (GRCO3) Green Rusts were studied in situ using synchrotron-based time-resolved small and wide angle X-ray scattering. The time-resolved data revealed, for the first time, the pH dependent transition from poorly-ordered schwertmannite (pH <6.5) into GRSO4 (pH ~6.8) followed by GRCO3 (at pH ~9.6). These data also showed that the addition of Zn to the starting sulphate Fe2+/Fe3+ solution resulted in a change in size of the GR unit-cell due to substitution of Zn into the GR structure.

scholarly journals Magnetic reconnection driven by filament eruption in the 7 June 2011 event

2013 ◽  
Vol 8 (S300) ◽  
pp. 502-503
Author(s):  
L. van Driel-Gesztelyi ◽  
D. Baker ◽  
T. Török ◽  
E. Pariat ◽  
L. M. Green ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Filament Eruption ◽  
Mhd Simulations ◽  
Reconnection Region ◽  
Solar Eruptions ◽  
Magnetic Modelling ◽  
First Time

AbstractDuring an unusually massive filament eruption on 7 June 2011, SDO/AIA imaged for the first time significant EUV emission around a magnetic reconnection region in the solar corona. The reconnection occurred between magnetic fields of the laterally expanding CME and a neighbouring active region. A pre-existing quasi-separatrix layer was activated in the process. This scenario is supported by data-constrained numerical simulations of the eruption. Observations show that dense cool filament plasma was re-directed and heated in situ, producing coronal-temperature emission around the reconnection region. These results provide the first direct observational evidence, supported by MHD simulations and magnetic modelling, that a large-scale re-configuration of the coronal magnetic field takes place during solar eruptions via the process of magnetic reconnection.

scholarly journals Spatial scales of temperature and salinity variability estimated from Argo observations

Ocean Science ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 1-7 ◽  
Author(s):  
F. Ninove ◽  
P.-Y. Le Traon ◽  
E. Remy ◽  
S. Guinehut
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Deep Ocean ◽  
General Tendency ◽  
Zero Crossing ◽  
Tropical Regions ◽  
Covariance Functions ◽  
Salinity Variability ◽  
First Time

Abstract. Argo observations from 2005 to 2013 are used to characterize spatial scales of temperature and salinity variations from the surface down to 1300 m. Simulations are first performed to analyze the sensitivity of results to Argo sampling; they show that several years of Argo observations are required to estimate spatial scales of ocean variability over 20°  ×  20° boxes. Spatial scales are then computed over several large-scale areas. Zonal and meridional spatial scales (Lx and Ly which are zero crossing of covariance functions) vary as expected with latitudes. Scales are of about 100 km at high latitudes and more of 700 km in the Indian and Pacific equatorial–tropical regions. Zonal and meridional scales are similar except in tropical–equatorial regions where zonal scales are much larger (by a factor of 2 to 3) than meridional scales. Spatial scales are the largest close to the surface and have a general tendency for temperature to increase in deeper layers. There are significant differences between temperature and salinity scales, in particular, in the deep ocean. Results are consistent with previous studies based on sparse in situ observations or satellite altimetry. They provide, however, for the first time a global description of temperature and salinity scales of variability and a characterization of their variations according to depths.

High-Resolution Dynamic Analysis of the Phase Transformation in Ge2Sb2Te5 Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 1199-1202
Author(s):  
Se Ahn Song ◽  
Wei Zhang ◽  
Hong Sik Jeong ◽  
Jin Gyu Kim ◽  
Youn Joong Kim
Keyword(s):  
Phase Transformation ◽  
Crystal Growth ◽  
High Resolution ◽  
Large Scale ◽  
Voltage Electron ◽  
Transmission Electron ◽  
In Situ Heating ◽  
First Time ◽  
Crystal Growth Behavior

Phase transformation and crystal growth behavior of Ge2Sb2Te5 were investigated systematically by means of in situ heating (from room temperature to 500 oC) of amorphous Ge2Sb2Te5 alloy in a high voltage electron microscope with real-time monitoring. Large-scale crystallization occurred to amorphous Ge2Sb2Te5 around 200 oC. Large crystal growth developed on heating from 200 oC to 400 oC, and single crystalline grains grew up to 150 nm. Eventually the onset of partial melting of thin Ge2Sb2Te5 foil was at 500 oC and liquid Ge2Sb2Te5 was observed for the first time by high-resolution transmission electron microscopy. Hexagonal Ge2Sb2Te5 phase remains after a subsequent cooling.

Light-induced structural evolution of photoswitchable carbohydrate-based surfactant micelles

2015 ◽  
Vol 51 (25) ◽  
pp. 5509-5512 ◽  
Author(s):  
Rico F. Tabor ◽  
Matthew J. Pottage ◽  
Christopher J. Garvey ◽  
Brendan L. Wilkinson
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Structural Changes ◽  
Structural Evolution ◽  
Time Resolved ◽  
Surfactant Micelles ◽  
First Time ◽  
Over Time

We report the light-induced structural evolution of photoswitchable carbohydrate-based surfactant micelles using time-resolved small-angle neutron scattering (TR-SANS), monitoring the structural changes in micellisation in situ over time and demonstrating for the first time the course and implications of this process.

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