Simulated X-ray Research Articles

Generative Adversarial Network (GAN) for Automatic Reconstruction of the 3D Spine Structure by Using Simulated Bi-Planar X-ray Images.

In this study, we modified the previously proposed X2CT-GAN to build a 2Dto3D-GAN of the spine. This study also incorporated the radiologist’s perspective in the adjustment of input signals to prove the feasibility of the automatic production of three-dimensional (3D) structures of the spine from simulated bi-planar two-dimensional (2D) X-ray images. Data from 1012 computed tomography (CT) studies of 984 patients were retrospectively collected. We tested this model under different dataset sizes (333, 666, and 1012) with different bone signal conditions to observe the training performance. A 10-fold cross-validation and five metrics—Dice similarity coefficient (DSC) value, Jaccard similarity coefficient (JSC), overlap volume (OV), and structural similarity index (SSIM)—were applied for model evaluation. The optimal mean values for DSC, JSC, OV, SSIM_anteroposterior (AP), and SSIM_Lateral (Lat) were 0.8192, 0.6984, 0.8624, 0.9261, and 0.9242, respectively. There was a significant improvement in the training performance under empirically enhanced bone signal conditions and with increasing training dataset sizes. These results demonstrate the potential of the clinical implantation of GAN for automatic production of 3D spine images from 2D images. This prototype model can serve as a foundation in future studies applying transfer learning for the development of advanced medical diagnostic techniques.

Anisotropy of 4f states in 3d−4f single-molecule magnets

We have measured angular-dependent fluorescence-yield x-ray magnetic circular dichroism spectra on single crystals of the heterometallic $3d\ensuremath{-}4f$ 12-metallacrown-4 ${\mathrm{TbMn}}_{4}$ and ${\mathrm{DyMn}}_{4}$ complexes. Simulated spectra using crystal-field multiplet calculations reproduce the experimentally observed spectra. The orientation of the molecules causes linear dichroism spectra of the $4f$ absorption spectra. This natural linear dichroism shows the anisotropic charge distribution of the rare-earth $4f$ state in the tetragonal crystal field despite the small $4f$ crystal-field splitting. The magnetic moment of the molecule is dominated by the rare-earth moment revealing a considerably large contribution of orbital moment. From a sum-rule analysis of experimental and simulated x-ray magnetic circular dichroism, we determined corrected spin and orbital Dy moments at low temperature (14 K) within a magnetic field of 7 T. We find a significant angular dependence of the Dy magnetic moments, indicating the presence of fourth-order magnetic anisotropy.

Topological nodal line semimetal in an all-sp 2 monoclinic carbon

Topological nodal line semimetal is an exotic class of quantum materials featuring the continuous line of nodes inside the first Brillouin zone. Here we identify by systematical ab initio calculations a new all-sp 2 hybridized carbon allotrope with monoclinic C2/c symmetry which is termed as bcm-C16. Total energy calculations show that our proposed bcm-C16 carbon is energetically comparable to or stable than the previously proposed bco-C16, bct-C16, and oP16 carbon. Its dynamical stability has been confirmed by phonon mode calculations. Detailed analysis of the electronic properties show that bcm-C16 carbon is a topological nodal line semimetal with a single closed nodal ring around the Γ high symmetric point, protected by spatial inversion and time-reversal symmetry. When the nodal ring is projected onto the (001) surface, a topologically protected drumhead-like surface state can be seen inside or outside the nodal ring depending on the different surface terminations. Moreover, we also examined the tensile-strain robustness of the electronic properties of bcm-C16 carbon. The nodal ring is robust under a tensile-strain along the crystalline x- and z-directions up to 20%. In addition, the simulated x-ray diffraction pattern (XRD) of bcm-C16 carbon matches with the experimental pattern found in the detonation and chimney soot experiment. The present proposal has enriched the family of carbon allotropes with topological nodal lines, and pave the way for further theoretical and experimental studies.

CAD-based x-ray CT calibration and error compensation

Artifacts due to imperfect determination of the scanner geometry, beam hardening (BH), and diffuse Compton scattering, limit the quantitative exploitation of radiographs or tomographies for non-destructive evaluation. Exploiting the computer-aided design (CAD) model of an industrial part, a methodology is proposed to refine the estimation of the computed tomography (CT)-scanner geometry up to a scale factor, to correct or account for artifacts, and to assess the metrology of the part. A projective model describing the formation of x-ray images in CT-scanners is first introduced. The optimal parameters of the projective model are identified using a novel CAD-based calibration method that relies on the registration of simulated projections onto experimental ones. A metrological analysis based on the comparison between acquired and simulated x-ray images is proposed. A turbine blade, for which an automatic inspection procedure from few views is under development, is used as an example to illustrate the proposed methodology. The parametrization accounts for the refinement of the projection geometry, the calibration of BH, and the estimation of scattering. It is shown that, using the proposed procedure, the differences between acquired and simulated radiographic images are significantly reduced, indicating that the optimal parameters are properly identified. These differences are then exploited to detect flaws in the part.

A Simple Method to Improve Detection of Femoral Nail Abutment in the Distal Femur: A Computer Modeling Study.

Proximal femur fractures are more frequently treated with long femoral nails. Lateral radiographs are used to assess the nail position in the distal femur. However, because of the asymmetric shape of the distal femur, standard lateral radiographs alone are suboptimal for assessing anteriorly positioned nails in the distal femur. Consequently, instances of nail abutment or even perforation might be missed intraoperatively. Using a three-dimensional (3D) modelling approach, we asked: When the nail is in the anterior fifth of the canal, will rotating the femur to align the simulated x-ray beam with the anterior femoral condyles instead of the posterior femoral condyles increase the diagnostic accuracy of detecting nail perforation of the anterior cortex? 3D models of 42 unilateral femora from a population sample representative of patients with hip fractures (mean age of 76 ± 7 years, 10 males and 32 females, and 16 left and 26 right femora) were used. The patients had a mean height of 158 ± 9 cm; 27 femora were from Asians and 15 were from Caucasians. Clinically appropriately sized nails had already been virtually implanted previously as part of a quantitative nail fit assessment study. In a preliminary step, the mean angles of inclination of the distal anterior supracondylar region were quantified using four axial sections of the distal femur. For the femora with the nail tip in the anterior fifth of the canal, projections representing a lateral radiograph were generated along with rotated projections at mean angle (5°, 8°) rotations, with the anterior femoral condyles aligned, and anterior femoral condyle alignment followed by internal and external rotation to detect maximum nail perforation. The distance from the nail to the distal anterior cortex was measured for each rotational projection and used to detect anterior nail perforation. The accuracy of detection was assessed using the area under the curve (AUC) of the receiver operating characteristic (ROC) analysis. Rotating the 3D models by aligning the x-ray beam with the anterior femoral condyles improves the diagnostic ability of detecting anterior nail perforation compared with standard lateral radiographs. The AUC increased with rotation from 0.50 (95% confidence interval 0.50 to 0.50) on the lateral projection to 0.73 (95% CI 0.57 to 0.88, difference = -0.23; p = 0.004) at 5° of rotation, 0.77 (95% CI 0.62 to 0.93, difference = -0.27; p = 0.001) at both 8° of rotation and with the anterior femoral condyles aligned, and to 0.82 (95% CI 0.67 to 0.97, difference = -0.32; p < 0.001) with internal/external rotations past the anterior femoral condyles. There were no differences in accuracy between the four methods of rotation. This study shows that rotating the femur to align the anterior femoral condyles on a lateral radiograph and then internally/externally rotating it, improves the accuracy assessed via the AUC of detecting anterior perforation when long nails are positioned in the anterior fifth of the distal femur. This approach can easily be used in a clinical setting. Intraoperatively, the image intensifier can be rotated around the leg to produce an image with the anterior femoral condyle aligned, providing surgeons with an opportunity to identify and improve the nail's position or exchange the nail while the patient is still under anesthesia.

Combination of Knoevenagel Polycondensation and Water-Assisted Dynamic Michael-Addition-Elimination for the Synthesis of Vinylene-Linked 2D Covalent Organic Frameworks.

Vinylene‐linked two‐dimensional conjugated covalent organic frameworks (V‐2D‐COFs), belonging to the class of two‐dimensional conjugated polymers, have attracted increasing attention due to their extended π‐conjugation over the 2D backbones associated with high chemical stability. The Knoevenagel polycondensation has been demonstrated as a robust synthetic method to provide cyano (CN)‐substituted V‐2D‐COFs with unique optoelectronic, magnetic, and redox properties. Despite the successful synthesis, it remains elusive for the relevant polymerization mechanism, which leads to relatively low crystallinity and poor reproducibility. In this work, we demonstrate the novel synthesis of CN‐substituted V‐2D‐COFs via the combination of Knoevenagel polycondensation and water‐assisted dynamic Michael‐addition‐elimination, abbreviated as KMAE polymerization. The existence of C=C bond exchange between two diphenylacrylonitriles (M1 and M6) is firstly confirmed via in situ high‐temperature NMR spectroscopy study of model reactions. Notably, the intermediate M4 synthesized via Michael‐addition can proceed the Michael‐elimination quantitatively, leading to an efficient C=C bond exchange, unambiguously confirming the dynamic nature of Michael‐addition‐elimination. Furthermore, the addition of water can significantly promote the reaction rate of Michael‐addition‐elimination for highly efficient C=C bond exchange within 5 mins. As a result, the KMAE polymerization provides a highly efficient strategy for the synthesis of CN‐substituted V‐2D‐COFs with high crystallinity, as demonstrated by four examples of V‐2D‐COF‐TFPB‐PDAN, V‐2D‐COF‐TFPT‐PDAN, V‐2D‐COF‐TFPB‐BDAN, and V‐2D‐COF‐HATN‐BDAN, based on the simulated and experimental powder X‐ray diffraction (PXRD) patterns as well as N2‐adsorption–desorption measurements. Moreover, high‐resolution transmission electron microscopy (HR‐TEM) analysis shows crystalline domain sizes ranging from 20 to 100 nm for the newly synthesized V‐2D‐COFs.

Trajectory Optimization in Computed Tomography Based on Object Geometry

We present a new approach for the task of trajectory optimization for X-ray computed tomography (CT) in a robot-based CT (RoboCT) application. An optimized trajectory corresponds to a projection set of predefined size that leads to a 3Dreconstruction with less image-artifacts than other possible sets of the same size. We incorporate prior knowledge through a model of the object and simulated X-ray projections of the interested scenario. We formulate the optimization problem as maximization of an objective function and solve it heuristically by means of a genetic algorithm. As objective function, we use a metric that correlates with the amount of edge information of a projection set, since we assume that this characteristic is important for a reconstruction with low image-artifacts. The metric is based on wavelet analysis of the projections. We carry out computer experiments for a test object made of homogeneous material. The optimized trajectory allows a sharp reconstruction of straight edges and clearly outperforms reconstructions from standard trajectories.

Investigations of structural, spectral (IR and NMR) and in silico analyses of boron compounds as SERM inhibitor

• Detail computational analyses were done over the boron compounds. • Structural and spectral characterizations were done in detail. • SERM properties of boron compounds were investigated. • Active amino acid chain was determined in estrogen receptor. • Leucine was found as the most active amino acid. Computational analyses of selected boron compounds are performed at M06–2X/6–31+ G (d,p) level in vacuum and water. Simulated X-Ray structure and structural parameters are reported. In spectral analyses, IR spectrum are examined with VEDA program and vibration modes of selected peaks in IR spectrum are revealed. As for the NMR spectrum, chemical shift value of carbon, hydrogen, nitrogen and boron atoms are calculated for studied compounds. In addition to characterization studies, electronic properties of studied boron compounds are investigated by the calculation of contour plots and MEP maps of mentioned compounds. Finally, anticancer properties of studied compounds are investigated by molecular docking calculations. 6VPK, estrogen receptor, is selected as target protein in this study. Selective estrogen receptor modulator (SERM) properties of studied compounds are investigated due to the fact that inhibiting of the estrogen receptor is one of the cancer preventions. As a result, compound ( 2 ) and ( 4 ) are the best drug candidates due to the fact that their results are similar to each other. Amino acids between 525 and 539 in target protein are determined as effective in targeted drug development. Finally, leucine is identified as the most interacting amino acid.

Event Detection and Reconstruction Using Neural Networks in TES Devices: a Case Study for Athena/X-IFU

Transition Edge Sensors detector devices, like the core of the X-IFU instrument that will be on-board the Athena X-ray Observatory, produce current pulses as a response to the incident X-ray photons. The reconstruction of these pulses has been traditionally performed by means of a triggering algorithm based on the derivative signal overcoming a threshold (detection) followed by an optimal filtering (to retrieve the energy of each event). However, when the arrival of the photons is very close in time, the triggering algorithm is incapable of detecting all the individual pulses which are thus piled-up. In order to improve the efficiency of the detection and energy-retrieval process, we study here an alternative approach based on Machine Learning techniques to process the pulses. For this purpose, we construct and train a series of Neural Networks (NNs) not only for the detection but also for the recovering of the arrival time and the energy of simulated X-ray pulses. The data set used to train the NNs consists of simulations performed with the sixte/xifusim software package, the Athena/X-IFU official simulator. The performance of our NN classification clearly surpasses the detection performance of the classical triggering approach for the full range of photon energy combinations, showing excellent metrics and very competitive computing efficiency. However, the precision obtained for the recovery of the energy of the photons cannot currently compete with the standard optimal filtering algorithm, despite its much better computing efficiency.

Theoretical Study on the Structure and Spectral Properties of Several Classical and Non-Classical C76 Isomers and Their Newly Synthesized Derivatives.

X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra, as well as the ground-state electronic/geometrical structures of the newly discovered two non-classical isomers C2-C76(NC2) and C1-C76(NC3) with their derivatives C2-C76(NC2)(CF3)14 and C1-C76(NC3)Cl24, as well as the non-IPR(isolated pentagon rule) isomer C1-#17418C76 with its embedded metal fullerene U@C1-#17418C76 have been calculated at the density functional theory (DFT) level. The electronic structure after chlorination is significantly different in the simulated X-ray spectrum. Both XPS and NEXAFS spectra reflect obvious isomer dependence, indicating that the "fingerprint" in X-ray spectroscopy can provide an effective means for the identification of the above-mentioned fullerene isomers. Time-dependent DFT was used to simulate the ultraviolet-visible absorption spectrum of U@C1-#17418C76. The calculated results are in good agreement with the experimental consequence. This work reveals that theoretically simulated X-ray and UV-vis spectroscopy techniques can provide valuable information to help researchers explore the electronic structure of fullerenes and the identification of isomers in future experimental and theoretical fields.

P2221-C8: A novel carbon allotrope denser than diamond

We present a new superdense and superhard carbon allotrope with P2221 space group and 8 atoms in the unit cell, naming P2221-C8. The density of P2221-C8 is 3.579 g/cm3, which is denser than diamond and even BC8. The energetical, dynamical and mechanical stabilities of P2221-C8 are confirmed by the calculation of energy, phonon frequencies and elastic constants, respectively. The hardness ranges from 88 GPa to 94 GPa according to different models, which is comparable with that of the diamond. The bandgap is indirect with 4.475 eV, which is smaller than that of the diamond. In addition, the match between simulated X-ray diffraction (XRD) and detonation experiments shows a possible way to synthesis it.

Fiber Optic RealShape (FORS) Technology for Endovascular Navigation in Severe Tortuous Vessels

Purpose: The purpose of this study was to describe the use of a wire and catheters embedded with optical fiber (Fiber Optic RealShape [FORS]) to catheterize tortuous target vessels avoiding radiation. Technique: A virtual biplane vies was simulated coupling traditional x-ray system, preoperative CT scan, and FORS system to treat an isolated hypogastric aneurysm. Despite the complex anatomy, catheterization of all target vessels was possible in 12 minutes with 19 seconds of fluoroscopy time (Radiation Exposure 3.8 mGy×cm2). A minimal invasive endovascular exclusion of the aneurysm was achieved through selective coil-embolization of the iliolumbar artery and implantation of balloon expandable covered stents, thus preserving the perfusion of the superior gluteal artery. Conclusion: FORS guidance allowed catheterization of a target vessel with challenging anatomy with a low radiation exposure.

Simulated sensor characterization for virtual clinical trials in mammography and digital breast tomosynthesis

Virtual clinical trials in X-ray breast imaging permit to compare different technical solutions and imaging modalities at reduced costs, involved personnel, reduced times and reduced radiation risks to patients. In this context, the detector characteristics (spatial resolution, noise level and efficiency) play a key role for an appropriate generation of simulated images. The project AGATA proposes to compute images as dose deposit maps in a detector layer of defined materials. Simulated images are then post-processed on the basis of suitable comparison between intrinsic characteristics of real and simulated detectors. With this scope, as first step for the post-processing manipulations, we evaluated the presampled modulation transfer function (MTF), the detector-response function and the noise power spectrum (NPS) of the simulated detectors. Two detectors were simulated: (1) 0.20 mm-thick a-Se direct flat panel with 70 µm pixel pitch and (2) CsI(Tl) indirect flat panel with 100 µm pixel pitch and scintillator layer 0.25 mm thick. In addition, the impact of simulating the de-excitation processes (Auger emission and fluorescence) was explored. Simulated detector characteristics were evaluated for W/Rh spectra between 25 kV and 31 kV. The in-silico platform used a Monte Carlo software based on Geant4 toolkit (vers. 6). First, the simulation and tracking of electrons generated from photoelectric or Compton interactions was shown to have neglectable influence on the pixel values for the explored spectra, with the produced electrons presenting short ranges with respect to the pixel dimension. In the case of the CsI detector, which has fluorescence energies higher than those of the simulated X-ray photons, the deexcitation processes have not noticeable influence on the calculated pixel values. On the other hand, the MTF of the a-Se detector resulted slightly lower when the fluorescence is simulated in the detector materials, due to the dose spread derived from the fluorescence photons, which can travel far from the initial ionization interaction. Regarding the a-Se detector, the noise power spectrum resulted lower with simulated deexcitation.

Molecular Insight into Microstructural and Dynamical Heterogeneities in Magnesium Ionic Liquid Electrolytes.

Ionic liquids (ILs) are promising designer solvents for multivalent electrolytes, enabling the modulation of molecular-level interactions of solvate species. The molecular mechanism of multivalent-ion clustering and its impact on electrolytes properties is far less studied than that of ion pairs. Herein, we explore the effect of ion clusters on the transport and electrochemical behavior of IL-based electrolytes for Mg batteries. Simulation and small-angle X-ray scattering results indicate that ILs with higher denticity effectively suppress ion agglomeration and parasitic reactions of the Mg electrolytes. Although ion clustering reduces the diffusivity of Mg2+, the Coulombic efficiency for the reversible Mg deposition/stripping process is improved, highlighting the importance of microstructural and dynamical heterogeneities in the rational design of enhanced multivalent electrolytes.

Sensitivity studies on the thermal beta+decay and thermal neutrino loss rates in the multizone X-ray burst model mesa

ABSTRACT Recently, it has been discovered that the beta+decay rates and neutrino loss rates of 64Ga and 68Se greatly affect the light curves and final abundances of X-ray bursts in a one-zone model in all circumstances. Here we further expand the study to the multizone model mesa and compare the results with observations of the bursting source GS 1826–24. It was found that the light curve of the modified beta decay rates of 64Ga is more comparable to observations than the standard beta decays. The final mass fractions of the ashes of the X-ray bursts for elements with a mass number of 38 (38Ar, 38Ca) are greatly modified because of the beta+decay rate and neutrino loss rate of 68Se. They also produce more URCA nuclei, which may lead to stronger cooling in the neutron star crusts. Both the modified rates of 68Se and 64Ga make the recurrence times of the simulated X-ray bursts longer because they cause more energy loss than the standard rates and more time is needed to accumulate energy to trigger the bursts.

Pressure-densified new rhombohedral phase of EuSn2As2

The magnetic topological insulator ${\mathrm{EuSn}}_{2}{\mathrm{As}}_{2}$ is known to crystallize in a ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$-type layered structure in rhombohedral symmetry at ambient conditions and undergo a structural phase transition toward a monoclinic $\ensuremath{\beta}$ phase under increasing pressure. Here, we identify by ab initio calculations a new high-pressure rhombohedral structure (termed the $\ensuremath{\gamma}$ phase) in $R\overline{3}m$ symmetry comprising Sn-As-As-Sn linear chains along the $z$ axis via the formation of As-As bonds in the AsSn/SnAs bilayers with strong anisotropic lattice distortion along the [001] orientation. This pressure-densified new rhombohedral phase has a metallic A-type antiferromagnetic ground state and is energetically more favorable than the original rhombohedral structure and the monoclinic $\ensuremath{\beta}$ phase above 11 GPa. Simulated x-ray diffraction patterns provide an excellent match to the previously unexplained distinct diffraction peak around $14.{7}^{\ensuremath{\circ}}$ found in experiments for ${\mathrm{EuSn}}_{2}{\mathrm{As}}_{2}$ above 13 GPa. These findings offer key insights into a new type of high-pressure phase of layered magnetic topological insulators, laying a foundation for further exploration of this intriguing class of materials.

Theoretical study of intermediate valence fluctuation in thulium selenide and electrical properties of TmSe1−xTex

The study of valence fluctuation is made on TmSe compound from simulated theoretical x-ray powder diffraction data. The theoretical lattice parameter is in agreement with experimental parameter. The amount of charge transfer is deduced as 0.23ē which proves the presence of intermediate valence fluctuation in the system. Further a theoretical Study is made on TmSe1−xTex (x = 0.5, 0.77, 0.83 and 1.00) to deduce electrical transport properties by using only two parameters, lattice constant and energy gap. The calculated transport properties electrical resistivity, carrier mobility, carrier concentration, carrier effective mass and dielectric constant are compared with the available experimental data which agrees with each other.

Nitrogen-doped redox graphene as a negative electrode additive for lead-acid batteries

To suppress the sulfation of the negative electrode of lead-acid batteries, a graphene derivative (GO-EDA) was prepared by ethylenediamine (EDA) functionalized graphene oxide (GO), which was used as an effective additive for the negative electrode of lead-acid batteries. The effect of GO-EDA on the performance of lead-acid batteries was studied by electrochemical methods, simulated cell performance test, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that when the negative active material (NAM) contains 0.5 wt.% GO-EDA additive (the N-0.5 cell), the initial discharge capacity of the cell at a rate of 0.05 C is 171.47 mAh g−1. Meanwhile, the high-rate partial state of charge (HRPSoC) cycle life of the N-0.5 cell under 1 C rate is 17,970 cycles, which is 280% higher than that of the blank control cell. In a word, GO-EDA has the potential to be applied to enhance the specific capacity and HRPSoC cycle-life of lead-acid batteries.

Anchoring HFO nanoparticles on MWCNTs as high electron transfer composite adsorbent for the removal of H2S at low temperature

As a significant component in desulfurizers, iron-based desulfurizer has already been widely investigated in the past decades because of their convenience, low cost and high sulfur capacity. In this work, the highly active hydrated ferric oxide (HFO) nanoparticles anchored on multi-walled carbon nanotubes (MWCNTs) were synthesized via the co-precipitation method. The result of the H2S breakthrough capacity test indicated that the low-temperature desulfurization performance of HFO was significantly promoted by adding of MWCNTs. The best desulfurization performance (144.2 mg g−1) was obtained using the sample with 20 wt% MWCNTs. The structure of formation of HFO is equivalent to the predicted structure by generating simulated powder X-ray diffraction patterns using the Reflex module of Material Studio 2019. The calculation results from VASP show the highly dispersed HFO nanoparticles were anchored on MWCNTs surface, which means the Fe-O-C bond was formed. The improved desulfurization performance was attributed to the dispersion of HFO nanoparticles and more exposed adsorption sites due to the strong interaction between MWCNTs and HFO.

Understanding Transports Dynamics inside PEMFC Using Combination between Direct Simulation and Operando X-Ray Computed Tomography

Computational Fluid Dynamics (CFD) with the Lattice Boltzmann Method (LBM) was used to simulate the temperature distribution and water saturation inside the porous gas diffusion and catalyst layers of polymer electrolyte membrane fuel cell (PEMFC) [1-3]. The model was validated with the images of liquid water saturation in the three dimensional micro-structure of porous layers taken by the in-operando X-ray computed tomography (CT) [4]. Meanwhile, the ultra-fine thermocouple was introduced into the operando PEMFC to obtain the temperature distribution at the various site in the porous layers, including at the interface of GDL under the channel and channel land, at the micro porous layer (MPL) and catalyst layer (CL) [5]. For this time, the model was validated with the temperature distribution data and the local saturation of water, heat transfer, species transport, and electrochemical kinetics were explored under different cell operating conditions. Figure 1 shows a comparison of simulation and experimental data (in operando X-ray CT and ultra-fine thermocouples) for the water saturation in the detailed structure of porous layer as well as the temperature distribution. The model was well validated. Implication between water saturation and cell over potentials will be presented and discussed.